diff --git a/android/jni/com/mapswithme/maps/Framework.cpp b/android/jni/com/mapswithme/maps/Framework.cpp
index b6d30d100c..9979a1181e 100644
--- a/android/jni/com/mapswithme/maps/Framework.cpp
+++ b/android/jni/com/mapswithme/maps/Framework.cpp
@@ -284,7 +284,7 @@ Storage & Framework::GetStorage()
   return m_work.GetStorage();
 }
 
-DataSourceBase const & Framework::GetIndex() { return m_work.GetIndex(); }
+DataSourceBase const & Framework::GetDataSource() { return m_work.GetDataSource(); }
 
 void Framework::ShowNode(TCountryId const & idx, bool zoomToDownloadButton)
 {
diff --git a/android/jni/com/mapswithme/maps/Framework.hpp b/android/jni/com/mapswithme/maps/Framework.hpp
index 902a055a34..bb75b5c2ad 100644
--- a/android/jni/com/mapswithme/maps/Framework.hpp
+++ b/android/jni/com/mapswithme/maps/Framework.hpp
@@ -81,7 +81,7 @@ namespace android
     Framework();
 
     storage::Storage & GetStorage();
-    DataSourceBase const & GetIndex();
+    DataSourceBase const & GetDataSource();
 
     void ShowNode(storage::TCountryId const & countryId, bool zoomToDownloadButton);
 
diff --git a/android/jni/com/mapswithme/maps/ugc/UGC.cpp b/android/jni/com/mapswithme/maps/ugc/UGC.cpp
index 0f58fb176e..e05b1ba77a 100644
--- a/android/jni/com/mapswithme/maps/ugc/UGC.cpp
+++ b/android/jni/com/mapswithme/maps/ugc/UGC.cpp
@@ -33,8 +33,8 @@ public:
     auto const version = static_cast<int64_t>(jversion);
     auto const index = static_cast<uint32_t>(jindex);
 
-    auto const & ix = g_framework->GetIndex();
-    auto const id = ix.GetMwmIdByCountryFile(platform::CountryFile(countryName));
+    auto const & ds = g_framework->GetDataSource();
+    auto const id = ds.GetMwmIdByCountryFile(platform::CountryFile(countryName));
     return FeatureID(id, index);
   }
 
diff --git a/editor/editor_tests/osm_editor_test.cpp b/editor/editor_tests/osm_editor_test.cpp
index acef4955e5..c5224b6c6c 100644
--- a/editor/editor_tests/osm_editor_test.cpp
+++ b/editor/editor_tests/osm_editor_test.cpp
@@ -53,7 +53,7 @@ public:
 };
 
 template <typename TFn>
-void ForEachCafeAtPoint(DataSourceBase & index, m2::PointD const & mercator, TFn && fn)
+void ForEachCafeAtPoint(DataSourceBase & dataSource, m2::PointD const & mercator, TFn && fn)
 {
   m2::RectD const rect = MercatorBounds::RectByCenterXYAndSizeInMeters(mercator, 0.2 /* rect width */);
 
@@ -65,7 +65,7 @@ void ForEachCafeAtPoint(DataSourceBase & index, m2::PointD const & mercator, TFn
     }
   };
 
-  index.ForEachInRect(f, rect, scales::GetUpperScale());
+  dataSource.ForEachInRect(f, rect, scales::GetUpperScale());
 }
 
 void FillEditableMapObject(osm::Editor const & editor, FeatureType const & ft, osm::EditableMapObject & emo)
@@ -147,7 +147,7 @@ EditorTest::EditorTest()
     LOG(LERROR, ("Classificator read error: ", e.what()));
   }
 
-  editor::tests_support::SetUpEditorForTesting(make_unique<search::EditorDelegate>(m_index));
+  editor::tests_support::SetUpEditorForTesting(make_unique<search::EditorDelegate>(m_dataSource));
 }
 
 EditorTest::~EditorTest()
@@ -174,7 +174,7 @@ void EditorTest::GetFeatureTypeInfoTest()
     builder.Add(cafe);
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     TEST(!editor.GetFeatureTypeInfo(ft.GetID().m_mwmId, ft.GetID().m_index), ());
 
@@ -202,7 +202,7 @@ void EditorTest::GetEditedFeatureTest()
     builder.Add(cafe);
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     FeatureType featureType;
     TEST(!editor.GetEditedFeature(ft.GetID(), featureType), ());
@@ -245,7 +245,7 @@ void EditorTest::SetIndexTest()
   osm::EditableMapObject emo;
   CreateCafeAtPoint({2.0, 2.0}, gbMwmId, emo);
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     auto const firstPtr = editor.GetOriginalFeature(ft.GetID());
     TEST(firstPtr, ());
@@ -255,7 +255,7 @@ void EditorTest::SetIndexTest()
     TEST_EQUAL(firstPtr->GetID(), secondPtr->GetID(), ());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     TEST_EQUAL(editor.GetOriginalFeatureStreet(ft), "Test street", ());
 
@@ -316,7 +316,7 @@ void EditorTest::GetEditedFeatureStreetTest()
     builder.Add(cafe);
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     string street;
     TEST(!editor.GetEditedFeatureStreet(ft.GetID(), street), ());
@@ -345,7 +345,7 @@ void EditorTest::GetFeatureStatusTest()
     builder.Add(unnamedCafe);
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     TEST_EQUAL(editor.GetFeatureStatus(ft.GetID()), FeatureStatus::Untouched, ());
 
@@ -359,7 +359,7 @@ void EditorTest::GetFeatureStatusTest()
     TEST_EQUAL(editor.GetFeatureStatus(emo.GetID()), FeatureStatus::Obsolete, ());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(2.0, 2.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(2.0, 2.0), [&editor](FeatureType & ft)
   {
     TEST_EQUAL(editor.GetFeatureStatus(ft.GetID()), FeatureStatus::Untouched, ());
     editor.DeleteFeature(ft.GetID());
@@ -384,7 +384,7 @@ void EditorTest::IsFeatureUploadedTest()
     builder.Add(TestPOI(m2::PointD(10, 10), "Corner Post", "default"));
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     TEST(!editor.IsFeatureUploaded(ft.GetID().m_mwmId, ft.GetID().m_index), ());
   });
@@ -423,7 +423,7 @@ void EditorTest::DeleteFeatureTest()
 
   TEST_EQUAL(editor.GetFeatureStatus(ft.GetID()), FeatureStatus::Untouched, ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     editor.DeleteFeature(ft.GetID());
     TEST_EQUAL(editor.GetFeatureStatus(ft.GetID()), FeatureStatus::Deleted, ());
@@ -475,7 +475,7 @@ void EditorTest::GetFeaturesByStatusTest()
 
   FeatureID modifiedId, deletedId, obsoleteId, createdId;
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor, &modifiedId](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor, &modifiedId](FeatureType & ft)
   {
     osm::EditableMapObject emo;
     FillEditableMapObject(editor, ft, emo);
@@ -485,13 +485,13 @@ void EditorTest::GetFeaturesByStatusTest()
     modifiedId = emo.GetID();
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(2.0, 2.0), [&editor, &deletedId](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(2.0, 2.0), [&editor, &deletedId](FeatureType & ft)
   {
     editor.DeleteFeature(ft.GetID());
     deletedId = ft.GetID();
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(3.0, 3.0), [&editor, &obsoleteId](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(3.0, 3.0), [&editor, &obsoleteId](FeatureType & ft)
   {
     editor.MarkFeatureAsObsolete(ft.GetID());
     obsoleteId = ft.GetID();
@@ -533,12 +533,12 @@ void EditorTest::OnMapDeregisteredTest()
     builder.Add(cafeMoscow);
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(2.0, 2.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(2.0, 2.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
@@ -566,7 +566,7 @@ void EditorTest::RollBackChangesTest()
 
   const string houseNumber = "4a";
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor, &houseNumber](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor, &houseNumber](FeatureType & ft)
   {
     osm::EditableMapObject emo;
     FillEditableMapObject(editor, ft, emo);
@@ -574,17 +574,17 @@ void EditorTest::RollBackChangesTest()
     TEST_EQUAL(editor.SaveEditedFeature(emo), osm::Editor::SaveResult::SavedSuccessfully, ());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&houseNumber](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&houseNumber](FeatureType & ft)
   {
     TEST_EQUAL(ft.GetHouseNumber(), houseNumber, ());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     editor.RollBackChanges(ft.GetID());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [](FeatureType & ft)
   {
     TEST_EQUAL(ft.GetHouseNumber(), "", ());
   });
@@ -602,7 +602,7 @@ void EditorTest::HaveMapEditsOrNotesToUploadTest()
 
   TEST(!editor.HaveMapEditsOrNotesToUpload(), ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
@@ -615,7 +615,7 @@ void EditorTest::HaveMapEditsOrNotesToUploadTest()
 
   editor.m_notes = Notes::MakeNotes(sf.GetFullPath(), true);
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     using NoteType = osm::Editor::NoteProblemType;
     feature::TypesHolder typesHolder;
@@ -646,7 +646,7 @@ void EditorTest::HaveMapEditsToUploadTest()
   TEST(!editor.HaveMapEditsToUpload(gbMwmId), ());
   TEST(!editor.HaveMapEditsToUpload(rfMwmId), ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
@@ -654,7 +654,7 @@ void EditorTest::HaveMapEditsToUploadTest()
   TEST(editor.HaveMapEditsToUpload(gbMwmId), ());
   TEST(!editor.HaveMapEditsToUpload(rfMwmId), ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(2.0, 2.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(2.0, 2.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
@@ -684,7 +684,7 @@ void EditorTest::GetStatsTest()
   TEST_EQUAL(stats.m_uploadedCount, 0, ());
   TEST_EQUAL(stats.m_lastUploadTimestamp, my::INVALID_TIME_STAMP, ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
@@ -692,7 +692,7 @@ void EditorTest::GetStatsTest()
   stats = editor.GetStats();
   TEST_EQUAL(stats.m_edits.size(), 1, ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(4.0, 4.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(4.0, 4.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
@@ -700,7 +700,7 @@ void EditorTest::GetStatsTest()
   stats = editor.GetStats();
   TEST_EQUAL(stats.m_edits.size(), 2, ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(5.0, 5.0), [](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(5.0, 5.0), [](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
   });
@@ -734,7 +734,7 @@ void EditorTest::IsCreatedFeatureTest()
     builder.Add(TestPOI(m2::PointD(10, 10), "Corner Post", "default"));
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     TEST(!editor.IsCreatedFeature(ft.GetID()), ());
     SetBuildingLevelsToOne(ft);
@@ -806,7 +806,7 @@ void EditorTest::CreateNoteTest()
     TEST_NOT_EQUAL(notes.front().m_note.find("Test name"), string::npos, ());
   };
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor, &createAndCheckNote](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor, &createAndCheckNote](FeatureType & ft)
   {
     createAndCheckNote(ft.GetID(), {1.0, 1.0}, osm::Editor::NoteProblemType::PlaceDoesNotExist);
 
@@ -815,7 +815,7 @@ void EditorTest::CreateNoteTest()
     TEST_EQUAL(editor.GetFeatureStatus(ft.GetID()), FeatureStatus::Obsolete, ());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(2.0, 2.0), [&editor, &createAndCheckNote](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(2.0, 2.0), [&editor, &createAndCheckNote](FeatureType & ft)
   {
     createAndCheckNote(ft.GetID(), {2.0, 2.0}, osm::Editor::NoteProblemType::General);
 
@@ -849,37 +849,37 @@ void EditorTest::LoadMapEditsTest()
 
   vector<FeatureID> features;
 
-  ForEachCafeAtPoint(m_index, m2::PointD(0.0, 0.0), [&features](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(0.0, 0.0), [&features](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
     features.emplace_back(ft.GetID());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor, &features](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor, &features](FeatureType & ft)
   {
     editor.DeleteFeature(ft.GetID());
     features.emplace_back(ft.GetID());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(2.0, 2.0), [&editor, &features](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(2.0, 2.0), [&editor, &features](FeatureType & ft)
   {
     editor.MarkFeatureAsObsolete(ft.GetID());
     features.emplace_back(ft.GetID());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(7.0, 7.0), [&features](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(7.0, 7.0), [&features](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
     features.emplace_back(ft.GetID());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(4.0, 4.0), [&editor, &features](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(4.0, 4.0), [&editor, &features](FeatureType & ft)
   {
     editor.DeleteFeature(ft.GetID());
     features.emplace_back(ft.GetID());
   });
 
-  ForEachCafeAtPoint(m_index, m2::PointD(6.0, 6.0), [&features](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(6.0, 6.0), [&features](FeatureType & ft)
   {
     SetBuildingLevelsToOne(ft);
     features.emplace_back(ft.GetID());
@@ -926,7 +926,7 @@ void EditorTest::LoadMapEditsTest()
 
   TEST_EQUAL(features.size(), loadedFeatures.size(), ());
 
-  m_index.DeregisterMap(m_mwmFiles.back().GetCountryFile());
+  m_dataSource.DeregisterMap(m_mwmFiles.back().GetCountryFile());
   TEST(RemoveMwm(newRfMwmId), ());
 
   TEST_EQUAL(editor.m_features.size(), 2, ());
@@ -949,7 +949,7 @@ void EditorTest::LoadMapEditsTest()
   TEST_EQUAL(editor.m_features.size(), 1, ());
   TEST_EQUAL(loadedFeatures.size(), 1, ());
 
-  m_index.DeregisterMap(m_mwmFiles.back().GetCountryFile());
+  m_dataSource.DeregisterMap(m_mwmFiles.back().GetCountryFile());
   TEST(RemoveMwm(gbMwmId), ());
 
   auto const newGbMwmId = BuildMwm("GB", [](TestMwmBuilder & builder)
@@ -985,7 +985,7 @@ void EditorTest::SaveEditedFeatureTest()
   TEST_EQUAL(editor.SaveEditedFeature(emo), osm::Editor::SaveResult::NothingWasChanged, ());
   TEST_EQUAL(editor.GetFeatureStatus(emo.GetID()), FeatureStatus::Created, ());
 
-  ForEachCafeAtPoint(m_index, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
+  ForEachCafeAtPoint(m_dataSource, m2::PointD(1.0, 1.0), [&editor](FeatureType & ft)
   {
     osm::EditableMapObject emo;
     FillEditableMapObject(editor, ft, emo);
diff --git a/editor/editor_tests/osm_editor_test.hpp b/editor/editor_tests/osm_editor_test.hpp
index 79d428c42f..a0c7829bd5 100644
--- a/editor/editor_tests/osm_editor_test.hpp
+++ b/editor/editor_tests/osm_editor_test.hpp
@@ -62,7 +62,7 @@ private:
       fn(builder);
     }
 
-    auto result = m_index.RegisterMap(file);
+    auto result = m_dataSource.RegisterMap(file);
     CHECK_EQUAL(result.second, MwmSet::RegResult::Success, ());
 
     auto const & id = result.first;
@@ -79,7 +79,7 @@ private:
   void Cleanup(platform::LocalCountryFile const & map);
   bool RemoveMwm(MwmSet::MwmId const & mwmId);
 
-  EditableDataSource m_index;
+  EditableDataSource m_dataSource;
   storage::CountryInfoGetterForTesting m_infoGetter;
   vector<platform::LocalCountryFile> m_mwmFiles;
 };
diff --git a/feature_list/feature_list.cpp b/feature_list/feature_list.cpp
index 4c3a94647c..0ef127a163 100644
--- a/feature_list/feature_list.cpp
+++ b/feature_list/feature_list.cpp
@@ -178,11 +178,11 @@ class Processor
   search::LocalityFinder m_finder;
 
 public:
-  Processor(DataSourceBase const & index)
-    : m_geocoder(index)
-    , m_boundariesTable(index)
+  Processor(DataSourceBase const & dataSource)
+    : m_geocoder(dataSource)
+    , m_boundariesTable(dataSource)
     , m_villagesCache(m_cancellable)
-    , m_finder(index, m_boundariesTable, m_villagesCache)
+    , m_finder(dataSource, m_boundariesTable, m_villagesCache)
   {
     m_boundariesTable.Load();
   }
@@ -324,23 +324,23 @@ int main(int argc, char ** argv)
   classificator::Load();
   classif().SortClassificator();
 
-  DataSource index;
+  DataSource dataSource;
   vector<platform::LocalCountryFile> mwms;
   platform::FindAllLocalMapsAndCleanup(numeric_limits<int64_t>::max() /* the latest version */,
                                        mwms);
   for (auto & mwm : mwms)
   {
     mwm.SyncWithDisk();
-    auto const & p = index.RegisterMap(mwm);
+    auto const & p = dataSource.RegisterMap(mwm);
     CHECK_EQUAL(MwmSet::RegResult::Success, p.second, ("Could not register map", mwm));
     MwmSet::MwmId const & id = p.first;
     CHECK(id.IsAlive(), ("Mwm is not alive?", mwm));
   }
 
-  Processor doProcess(index);
+  Processor doProcess(dataSource);
   PrintHeader();
   vector<shared_ptr<MwmInfo>> mwmInfos;
-  index.GetMwmsInfo(mwmInfos);
+  dataSource.GetMwmsInfo(mwmInfos);
   for (auto const & mwmInfo : mwmInfos)
   {
     if (mwmInfo->GetType() != MwmInfo::COUNTRY)
@@ -353,7 +353,7 @@ int main(int argc, char ** argv)
     map<uint32_t, osm::Id> featureIdToOsmId;
     ParseFeatureIdToOsmIdMapping(osmToFeatureFile, featureIdToOsmId);
     MwmSet::MwmId mwmId(mwmInfo);
-    DataSource::FeaturesLoaderGuard loader(index, mwmId);
+    DataSource::FeaturesLoaderGuard loader(dataSource, mwmId);
     for (uint32_t ftIndex = 0; ftIndex < loader.GetNumFeatures(); ftIndex++)
     {
       FeatureType ft;
diff --git a/generator/cities_boundaries_builder.cpp b/generator/cities_boundaries_builder.cpp
index f70a0c71c6..1f8a09ece6 100644
--- a/generator/cities_boundaries_builder.cpp
+++ b/generator/cities_boundaries_builder.cpp
@@ -67,11 +67,11 @@ bool ParseFeatureIdToTestIdMapping(string const & path, map<uint32_t, vector<uin
 
 CBV GetLocalities(string const & dataPath)
 {
-  DataSource index;
-  auto const result = index.Register(platform::LocalCountryFile::MakeTemporary(dataPath));
+  DataSource dataSource;
+  auto const result = dataSource.Register(platform::LocalCountryFile::MakeTemporary(dataPath));
   CHECK_EQUAL(result.second, MwmSet::RegResult::Success, ("Can't register", dataPath));
 
-  search::MwmContext context(index.GetMwmHandleById(result.first));
+  search::MwmContext context(dataSource.GetMwmHandleById(result.first));
   return search::CategoriesCache(LocalitiesSource{}, base::Cancellable{}).Get(context);
 }
 
diff --git a/generator/generator_tests/altitude_test.cpp b/generator/generator_tests/altitude_test.cpp
index fc38f4ab04..8bfc8d682b 100644
--- a/generator/generator_tests/altitude_test.cpp
+++ b/generator/generator_tests/altitude_test.cpp
@@ -131,10 +131,10 @@ void BuildMwmWithoutAltitudes(vector<TPoint3DList> const & roads, LocalCountryFi
     builder.Add(generator::tests_support::TestStreet(ExtractPoints(geom3D), std::string(), std::string()));
 }
 
-void TestAltitudes(DataSourceBase const & index, MwmSet::MwmId const & mwmId, std::string const & mwmPath,
+void TestAltitudes(DataSourceBase const & dataSource, MwmSet::MwmId const & mwmId, std::string const & mwmPath,
                    bool hasAltitudeExpected, AltitudeGetter & expectedAltitudes)
 {
-  AltitudeLoader loader(index, mwmId);
+  AltitudeLoader loader(dataSource, mwmId);
   TEST_EQUAL(loader.HasAltitudes(), hasAltitudeExpected, ());
 
   auto processor = [&expectedAltitudes, &loader](FeatureType const & f, uint32_t const & id)
@@ -181,11 +181,11 @@ void TestAltitudesBuilding(vector<TPoint3DList> const & roads, bool hasAltitudeE
   BuildRoadAltitudes(mwmPath, altitudeGetter);
 
   // Reading from mwm and testing altitude information.
-  DataSource index;
-  auto const regResult = index.RegisterMap(country);
+  DataSource dataSource;
+  auto const regResult = dataSource.RegisterMap(country);
   TEST_EQUAL(regResult.second, MwmSet::RegResult::Success, ());
 
-  TestAltitudes(index, regResult.first /* mwmId */, mwmPath, hasAltitudeExpected, altitudeGetter);
+  TestAltitudes(dataSource, regResult.first /* mwmId */, mwmPath, hasAltitudeExpected, altitudeGetter);
 }
 
 void TestBuildingAllFeaturesHaveAltitude(vector<TPoint3DList> const & roads, bool hasAltitudeExpected)
diff --git a/generator/generator_tests_support/test_with_custom_mwms.hpp b/generator/generator_tests_support/test_with_custom_mwms.hpp
index e3bfdc0191..06409815c3 100644
--- a/generator/generator_tests_support/test_with_custom_mwms.hpp
+++ b/generator/generator_tests_support/test_with_custom_mwms.hpp
@@ -47,7 +47,7 @@ public:
       fn(builder);
     }
 
-    auto result = m_index.RegisterMap(file);
+    auto result = m_dataSource.RegisterMap(file);
     CHECK_EQUAL(result.second, MwmSet::RegResult::Success, ());
 
     auto const id = result.first;
@@ -66,7 +66,7 @@ public:
     if (it == m_files.end())
       return;
 
-    m_index.DeregisterMap(file);
+    m_dataSource.DeregisterMap(file);
     Cleanup(*it);
     m_files.erase(it);
   }
@@ -88,7 +88,7 @@ protected:
 
   virtual void OnMwmBuilt(MwmInfo const & /* info */) {}
 
-  EditableDataSource m_index;
+  EditableDataSource m_dataSource;
   std::vector<platform::LocalCountryFile> m_files;
 };
 }  // namespace tests_support
diff --git a/generator/search_index_builder.cpp b/generator/search_index_builder.cpp
index 4f3ead1caa..f1fe253d77 100644
--- a/generator/search_index_builder.cpp
+++ b/generator/search_index_builder.cpp
@@ -323,11 +323,11 @@ void BuildAddressTable(FilesContainerR & container, Writer & writer)
   uint32_t address = 0, missing = 0;
   map<size_t, size_t> bounds;
 
-  DataSource mwmIndex;
+  DataSource dataSource;
   /// @ todo Make some better solution, or legalize MakeTemporary.
-  auto const res = mwmIndex.RegisterMap(platform::LocalCountryFile::MakeTemporary(container.GetFileName()));
+  auto const res = dataSource.RegisterMap(platform::LocalCountryFile::MakeTemporary(container.GetFileName()));
   ASSERT_EQUAL(res.second, MwmSet::RegResult::Success, ());
-  search::ReverseGeocoder rgc(mwmIndex);
+  search::ReverseGeocoder rgc(dataSource);
 
   {
     FixedBitsDDVector<3, FileReader>::Builder<Writer> building2Street(writer);
diff --git a/generator/sponsored_dataset_inl.hpp b/generator/sponsored_dataset_inl.hpp
index cc0f077a08..09dcd46dcc 100644
--- a/generator/sponsored_dataset_inl.hpp
+++ b/generator/sponsored_dataset_inl.hpp
@@ -20,8 +20,8 @@ class AddressMatcher
 public:
   AddressMatcher()
   {
-    LoadIndex(m_index);
-    m_coder = make_unique<search::ReverseGeocoder>(m_index);
+    LoadDataSource(m_dataSource);
+    m_coder = make_unique<search::ReverseGeocoder>(m_dataSource);
   }
 
   template <typename SponsoredObject>
@@ -34,7 +34,7 @@ public:
   }
 
 private:
-  DataSource m_index;
+  DataSource m_dataSource;
   std::unique_ptr<search::ReverseGeocoder> m_coder;
 };
 
diff --git a/generator/transit_generator.cpp b/generator/transit_generator.cpp
index 86da85f2c6..fe7208b096 100644
--- a/generator/transit_generator.cpp
+++ b/generator/transit_generator.cpp
@@ -72,7 +72,7 @@ void CalculateBestPedestrianSegments(string const & mwmPath, TCountryId const &
                                      GraphData & graphData)
 {
   // Creating IndexRouter.
-  SingleMwmDataSource index(mwmPath);
+  SingleMwmDataSource dataSource(mwmPath);
 
   auto infoGetter = storage::CountryInfoReader::CreateCountryInfoReader(GetPlatform());
   CHECK(infoGetter, ());
@@ -86,15 +86,15 @@ void CalculateBestPedestrianSegments(string const & mwmPath, TCountryId const &
     return infoGetter->GetLimitRectForLeaf(c);
   };
 
-  CHECK_EQUAL(index.GetMwmId().GetInfo()->GetType(), MwmInfo::COUNTRY, ());
+  CHECK_EQUAL(dataSource.GetMwmId().GetInfo()->GetType(), MwmInfo::COUNTRY, ());
   auto numMwmIds = make_shared<NumMwmIds>();
   numMwmIds->RegisterFile(CountryFile(countryId));
 
-  // Note. |indexRouter| is valid while |index| is valid.
+  // Note. |indexRouter| is valid while |dataSource| is valid.
   IndexRouter indexRouter(VehicleType::Pedestrian, false /* load altitudes */,
                           CountryParentNameGetterFn(), countryFileGetter, getMwmRectByName,
                           numMwmIds, MakeNumMwmTree(*numMwmIds, *infoGetter),
-                          traffic::TrafficCache(), index.GetIndex());
+                          traffic::TrafficCache(), dataSource.GetDataSource());
   auto worldGraph = indexRouter.MakeSingleMwmWorldGraph();
 
   // Looking for the best segment for every gate.
diff --git a/generator/utils.cpp b/generator/utils.cpp
index bbb0b51e85..235fe2c175 100644
--- a/generator/utils.cpp
+++ b/generator/utils.cpp
@@ -9,7 +9,7 @@
 
 namespace generator
 {
-// SingleMwmIndex ---------------------------------------------------------------------------------
+// SingleMwmDataSource -----------------------------------------------------------------------------
 SingleMwmDataSource::SingleMwmDataSource(std::string const & mwmPath)
 {
   m_countryFile = platform::LocalCountryFile::MakeTemporary(mwmPath);
@@ -18,13 +18,13 @@ SingleMwmDataSource::SingleMwmDataSource(std::string const & mwmPath)
       m_countryFile.GetFiles(), MapOptions::MapWithCarRouting,
       ("No correct mwm corresponding to local country file:", m_countryFile, ". Path:", mwmPath));
 
-  auto const result = m_index.Register(m_countryFile);
+  auto const result = m_dataSource.Register(m_countryFile);
   CHECK_EQUAL(result.second, MwmSet::RegResult::Success, ());
   CHECK(result.first.IsAlive(), ());
   m_mwmId = result.first;
 }
 
-void LoadIndex(DataSourceBase & index)
+void LoadDataSource(DataSourceBase & dataSource)
 {
   vector<platform::LocalCountryFile> localFiles;
 
@@ -36,7 +36,7 @@ void LoadIndex(DataSourceBase & index)
     LOG(LINFO, ("Found mwm:", localFile));
     try
     {
-      index.RegisterMap(localFile);
+      dataSource.RegisterMap(localFile);
     }
     catch (RootException const & ex)
     {
diff --git a/generator/utils.hpp b/generator/utils.hpp
index cbd469d2eb..037eee5d84 100644
--- a/generator/utils.hpp
+++ b/generator/utils.hpp
@@ -22,20 +22,20 @@ namespace generator
 class SingleMwmDataSource
 {
 public:
-  /// \param mwmPath is a path to mwm which should be registerd in Index.
+  /// \param mwmPath is a path to mwm which should be registerd in DataSource.
   explicit SingleMwmDataSource(std::string const & mwmPath);
 
-  DataSourceBase & GetIndex() { return m_index; }
+  DataSourceBase & GetDataSource() { return m_dataSource; }
   std::string GetPath(MapOptions file) const { return m_countryFile.GetPath(file); }
   MwmSet::MwmId const & GetMwmId() const { return m_mwmId; }
 
 private:
-  DataSource m_index;
+  DataSource m_dataSource;
   platform::LocalCountryFile m_countryFile;
   MwmSet::MwmId m_mwmId;
 };
 
-void LoadIndex(DataSourceBase & index);
+void LoadDataSource(DataSourceBase & dataSource);
 
 template <typename ToDo>
 bool ForEachOsmId2FeatureId(std::string const & path, ToDo && toDo)
diff --git a/generator/viator_dataset.cpp b/generator/viator_dataset.cpp
index 12155d87d4..07fdda0edf 100644
--- a/generator/viator_dataset.cpp
+++ b/generator/viator_dataset.cpp
@@ -56,8 +56,8 @@ ostream & operator<<(ostream & s, ViatorCity const & h)
 ViatorDataset::ViatorDataset(std::string const & dataPath)
   : m_storage(3000.0 /* distanceLimitMeters */, 3 /* maxSelectedElements */)
 {
-  LoadIndex(m_index);
-  m_cityFinder = make_unique<search::CityFinder>(m_index);
+  LoadDataSource(m_dataSource);
+  m_cityFinder = make_unique<search::CityFinder>(m_dataSource);
 
   m_storage.LoadData(dataPath);
 }
diff --git a/generator/viator_dataset.hpp b/generator/viator_dataset.hpp
index 98cb821283..0b0ecdca8c 100644
--- a/generator/viator_dataset.hpp
+++ b/generator/viator_dataset.hpp
@@ -50,7 +50,7 @@ public:
 
 private:
   SponsoredObjectStorage<ViatorCity> m_storage;
-  DataSource m_index;
+  DataSource m_dataSource;
   std::unique_ptr<search::CityFinder> m_cityFinder;
 };
 }  // namespace generator
diff --git a/indexer/altitude_loader.cpp b/indexer/altitude_loader.cpp
index 65c3748219..8e54d52034 100644
--- a/indexer/altitude_loader.cpp
+++ b/indexer/altitude_loader.cpp
@@ -31,8 +31,8 @@ void LoadAndMap(size_t dataSize, ReaderSource<FilesContainerR::TReader> & src, T
 
 namespace feature
 {
-AltitudeLoader::AltitudeLoader(DataSourceBase const & index, MwmSet::MwmId const & mwmId)
-  : m_handle(index.GetMwmHandleById(mwmId))
+AltitudeLoader::AltitudeLoader(DataSourceBase const & dataSource, MwmSet::MwmId const & mwmId)
+  : m_handle(dataSource.GetMwmHandleById(mwmId))
 {
   if (!m_handle.IsAlive())
     return;
diff --git a/indexer/altitude_loader.hpp b/indexer/altitude_loader.hpp
index 81a7cca025..ceb089e7e2 100644
--- a/indexer/altitude_loader.hpp
+++ b/indexer/altitude_loader.hpp
@@ -17,7 +17,7 @@ namespace feature
 class AltitudeLoader
 {
 public:
-  AltitudeLoader(DataSourceBase const & index, MwmSet::MwmId const & mwmId);
+  AltitudeLoader(DataSourceBase const & dataSource, MwmSet::MwmId const & mwmId);
 
   /// \returns altitude of feature with |featureId|. All items of the returned vector are valid
   /// or the returned vector is empty.
diff --git a/indexer/data_source.hpp b/indexer/data_source.hpp
index 5a0c8f3b7e..8e8edfb2d0 100644
--- a/indexer/data_source.hpp
+++ b/indexer/data_source.hpp
@@ -237,8 +237,8 @@ public:
   class FeaturesLoaderGuard
   {
   public:
-    FeaturesLoaderGuard(DataSourceBase const & index, MwmId const & id)
-      : m_handle(index.GetMwmHandleById(id)), m_source(m_handle)
+    FeaturesLoaderGuard(DataSourceBase const & dataSource, MwmId const & id)
+      : m_handle(dataSource.GetMwmHandleById(id)), m_source(m_handle)
     {
     }
 
diff --git a/indexer/data_source_helpers.cpp b/indexer/data_source_helpers.cpp
index 9f46af8f39..210a0af1e9 100644
--- a/indexer/data_source_helpers.cpp
+++ b/indexer/data_source_helpers.cpp
@@ -6,45 +6,44 @@
 
 namespace indexer
 {
-void ForEachFeatureAtPoint(DataSourceBase const & index, function<void(FeatureType &)> && fn, m2::PointD const & mercator, double toleranceInMeters)
+void ForEachFeatureAtPoint(DataSourceBase const & dataSource, function<void(FeatureType &)> && fn,
+                           m2::PointD const & mercator, double toleranceInMeters)
 {
   double constexpr kSelectRectWidthInMeters = 1.1;
   double constexpr kMetersToLinearFeature = 3;
   int constexpr kScale = scales::GetUpperScale();
-  m2::RectD const rect = MercatorBounds::RectByCenterXYAndSizeInMeters(mercator, kSelectRectWidthInMeters);
+  m2::RectD const rect =
+      MercatorBounds::RectByCenterXYAndSizeInMeters(mercator, kSelectRectWidthInMeters);
 
-  auto const emitter = [&fn, &rect, &mercator, toleranceInMeters](FeatureType & ft)
-  {
-   switch (ft.GetFeatureType())
-   {
-     case feature::GEOM_POINT:
-       if (rect.IsPointInside(ft.GetCenter()))
-         fn(ft);
-       break;
-     case feature::GEOM_LINE:
-       if (feature::GetMinDistanceMeters(ft, mercator) < kMetersToLinearFeature)
-         fn(ft);
-       break;
-     case feature::GEOM_AREA:
-     {
-       auto limitRect = ft.GetLimitRect(kScale);
-       // Be a little more tolerant. When used by editor mercator is given
-       // with some error, so we must extend limit rect a bit.
-       limitRect.Inflate(MercatorBounds::GetCellID2PointAbsEpsilon(),
-                         MercatorBounds::GetCellID2PointAbsEpsilon());
-       if (limitRect.IsPointInside(mercator) &&
-           feature::GetMinDistanceMeters(ft, mercator) <= toleranceInMeters)
-       {
-         fn(ft);
-       }
-     }
-       break;
-     case feature::GEOM_UNDEFINED:
-       ASSERT(false, ("case feature::GEOM_UNDEFINED"));
-       break;
-   }
+  auto const emitter = [&fn, &rect, &mercator, toleranceInMeters](FeatureType & ft) {
+    switch (ft.GetFeatureType())
+    {
+    case feature::GEOM_POINT:
+      if (rect.IsPointInside(ft.GetCenter()))
+        fn(ft);
+      break;
+    case feature::GEOM_LINE:
+      if (feature::GetMinDistanceMeters(ft, mercator) < kMetersToLinearFeature)
+        fn(ft);
+      break;
+    case feature::GEOM_AREA:
+    {
+      auto limitRect = ft.GetLimitRect(kScale);
+      // Be a little more tolerant. When used by editor mercator is given
+      // with some error, so we must extend limit rect a bit.
+      limitRect.Inflate(MercatorBounds::GetCellID2PointAbsEpsilon(),
+                        MercatorBounds::GetCellID2PointAbsEpsilon());
+      if (limitRect.IsPointInside(mercator) &&
+          feature::GetMinDistanceMeters(ft, mercator) <= toleranceInMeters)
+      {
+        fn(ft);
+      }
+    }
+    break;
+    case feature::GEOM_UNDEFINED: ASSERT(false, ("case feature::GEOM_UNDEFINED")); break;
+    }
   };
 
-  index.ForEachInRect(emitter, rect, kScale);
+  dataSource.ForEachInRect(emitter, rect, kScale);
 }
 }  // namespace indexer
diff --git a/indexer/data_source_helpers.hpp b/indexer/data_source_helpers.hpp
index f3fa1a5157..f7dc7a4582 100644
--- a/indexer/data_source_helpers.hpp
+++ b/indexer/data_source_helpers.hpp
@@ -9,6 +9,6 @@ class FeatureType;
 
 namespace indexer
 {
-void ForEachFeatureAtPoint(DataSourceBase const & index, function<void(FeatureType &)> && fn,
+void ForEachFeatureAtPoint(DataSourceBase const & dataSource, function<void(FeatureType &)> && fn,
                            m2::PointD const & mercator, double toleranceInMeters = 0.0);
 }
diff --git a/indexer/indexer_tests/CMakeLists.txt b/indexer/indexer_tests/CMakeLists.txt
index 5542d88f33..650b64dc7a 100644
--- a/indexer/indexer_tests/CMakeLists.txt
+++ b/indexer/indexer_tests/CMakeLists.txt
@@ -10,6 +10,7 @@ set(
   centers_table_test.cpp
   checker_test.cpp
   cities_boundaries_serdes_tests.cpp
+  data_source_test.cpp
   drules_selector_parser_test.cpp
   editable_map_object_test.cpp
   feature_metadata_test.cpp
@@ -17,7 +18,6 @@ set(
   features_offsets_table_test.cpp
   features_vector_test.cpp
   index_builder_test.cpp
-  index_test.cpp
   interval_index_test.cpp
   locality_index_test.cpp
   mwm_set_test.cpp
diff --git a/indexer/indexer_tests/index_test.cpp b/indexer/indexer_tests/data_source_test.cpp
similarity index 83%
rename from indexer/indexer_tests/index_test.cpp
rename to indexer/indexer_tests/data_source_test.cpp
index 0b59c41b74..c5b64905da 100644
--- a/indexer/indexer_tests/index_test.cpp
+++ b/indexer/indexer_tests/data_source_test.cpp
@@ -25,12 +25,12 @@ using platform::LocalCountryFile;
 
 namespace
 {
-class IndexTest : public MwmSet::Observer
+class DataSourceTest : public MwmSet::Observer
 {
 public:
-  IndexTest() { TEST(m_index.AddObserver(*this), ()); }
+  DataSourceTest() { TEST(m_dataSource.AddObserver(*this), ()); }
 
-  ~IndexTest() override { TEST(m_index.RemoveObserver(*this), ()); }
+  ~DataSourceTest() override { TEST(m_dataSource.RemoveObserver(*this), ()); }
 
   void ExpectRegistered(platform::LocalCountryFile const & localFile)
   {
@@ -86,21 +86,21 @@ protected:
     events.emplace_back(forward<TArgs>(args)...);
   }
 
-  DataSource m_index;
+  DataSource m_dataSource;
   vector<MwmSet::Event> m_expected;
   vector<MwmSet::Event> m_actual;
 };
 }  // namespace
 
-UNIT_CLASS_TEST(IndexTest, Parse)
+UNIT_CLASS_TEST(DataSourceTest, Parse)
 {
-  UNUSED_VALUE(m_index.RegisterMap(platform::LocalCountryFile::MakeForTesting("minsk-pass")));
+  UNUSED_VALUE(m_dataSource.RegisterMap(platform::LocalCountryFile::MakeForTesting("minsk-pass")));
 
   // Make sure that index is actually parsed.
-  m_index.ForEachInScale([](FeatureType &) { return; }, 15);
+  m_dataSource.ForEachInScale([](FeatureType &) { return; }, 15);
 }
 
-UNIT_CLASS_TEST(IndexTest, StatusNotifications)
+UNIT_CLASS_TEST(DataSourceTest, StatusNotifications)
 {
   string const mapsDir = GetPlatform().WritableDir();
   CountryFile const country("minsk-pass");
@@ -115,7 +115,7 @@ UNIT_CLASS_TEST(IndexTest, StatusNotifications)
 
   // Checks that observers are triggered after map registration.
   {
-    auto result = m_index.RegisterMap(file1);
+    auto result = m_dataSource.RegisterMap(file1);
     TEST_EQUAL(MwmSet::RegResult::Success, result.second, ());
 
     id1 = result.first;
@@ -127,7 +127,7 @@ UNIT_CLASS_TEST(IndexTest, StatusNotifications)
 
   // Checks that map can't registered twice.
   {
-    auto result = m_index.RegisterMap(file1);
+    auto result = m_dataSource.RegisterMap(file1);
     TEST_EQUAL(MwmSet::RegResult::VersionAlreadyExists, result.second, ());
 
     TEST(result.first.IsAlive(), ());
@@ -139,7 +139,7 @@ UNIT_CLASS_TEST(IndexTest, StatusNotifications)
   // Checks that observers are notified when map is updated.
   MwmSet::MwmId id2;
   {
-    auto result = m_index.RegisterMap(file2);
+    auto result = m_dataSource.RegisterMap(file2);
     TEST_EQUAL(MwmSet::RegResult::Success, result.second, ());
 
     id2 = result.first;
@@ -155,10 +155,10 @@ UNIT_CLASS_TEST(IndexTest, StatusNotifications)
   // leaving the inner block the map should be deregistered.
   {
     {
-      MwmSet::MwmHandle const handle = m_index.GetMwmHandleByCountryFile(country);
+      MwmSet::MwmHandle const handle = m_dataSource.GetMwmHandleByCountryFile(country);
       TEST(handle.IsAlive(), ());
 
-      TEST(!m_index.DeregisterMap(country), ());
+      TEST(!m_dataSource.DeregisterMap(country), ());
       TEST(CheckExpectations(), ());
     }
 
diff --git a/indexer/indexer_tests/features_vector_test.cpp b/indexer/indexer_tests/features_vector_test.cpp
index 8d8b7f6114..ed0fdb80e6 100644
--- a/indexer/indexer_tests/features_vector_test.cpp
+++ b/indexer/indexer_tests/features_vector_test.cpp
@@ -50,12 +50,12 @@ UNIT_TEST(FeaturesVectorTest_ParseMetadata)
 
   LocalCountryFile localFile = LocalCountryFile::MakeForTesting(kCountryName);
 
-  DataSource index;
-  auto result = index.RegisterMap(localFile);
+  DataSource dataSource;
+  auto result = dataSource.RegisterMap(localFile);
   TEST_EQUAL(result.second, MwmSet::RegResult::Success, ());
 
   auto const & id = result.first;
-  MwmSet::MwmHandle handle = index.GetMwmHandleById(id);
+  MwmSet::MwmHandle handle = dataSource.GetMwmHandleById(id);
   TEST(handle.IsAlive(), ());
 
   auto const * value = handle.GetValue<MwmValue>();
diff --git a/indexer/indexer_tests/index_builder_test.cpp b/indexer/indexer_tests/index_builder_test.cpp
index f13662a455..aa60d56f1a 100644
--- a/indexer/indexer_tests/index_builder_test.cpp
+++ b/indexer/indexer_tests/index_builder_test.cpp
@@ -52,11 +52,11 @@ UNIT_TEST(BuildIndexTest)
 
   {
     // Check that index actually works.
-    DataSource index;
-    UNUSED_VALUE(index.Register(platform::LocalCountryFile::MakeForTesting("build_index_test")));
+    DataSource dataSource;
+    UNUSED_VALUE(dataSource.Register(platform::LocalCountryFile::MakeForTesting("build_index_test")));
 
     // Make sure that index is actually parsed.
-    index.ForEachInScale([](FeatureType &) { return; }, 15);
+    dataSource.ForEachInScale([](FeatureType &) { return; }, 15);
   }
 
   // Clean after the test.
diff --git a/indexer/indexer_tests/rank_table_test.cpp b/indexer/indexer_tests/rank_table_test.cpp
index 359c3db3b4..54f9a78b62 100644
--- a/indexer/indexer_tests/rank_table_test.cpp
+++ b/indexer/indexer_tests/rank_table_test.cpp
@@ -97,8 +97,8 @@ UNIT_TEST(RankTableBuilder_EndToEnd)
     search::RankTableBuilder::Create(ranks, wcont);
   }
 
-  DataSource index;
-  auto regResult = index.RegisterMap(localFile);
+  DataSource dataSource;
+  auto regResult = dataSource.RegisterMap(localFile);
   TEST_EQUAL(regResult.second, MwmSet::RegResult::Success, ());
 
   TestTable(ranks, mapPath);
diff --git a/indexer/indexer_tests/scale_index_reading_tests.cpp b/indexer/indexer_tests/scale_index_reading_tests.cpp
index 9bbf2bb6da..4718f14445 100644
--- a/indexer/indexer_tests/scale_index_reading_tests.cpp
+++ b/indexer/indexer_tests/scale_index_reading_tests.cpp
@@ -54,7 +54,7 @@ public:
                                       [&](uint32_t index) { indices.push_back(index); });
     }
 
-    DataSource::FeaturesLoaderGuard loader(m_index, id);
+    DataSource::FeaturesLoaderGuard loader(m_dataSource, id);
 
     Names names;
     for (auto const & index : indices)
diff --git a/map/address_finder.cpp b/map/address_finder.cpp
index 49e7f76e1e..b2eaa3f3f2 100644
--- a/map/address_finder.cpp
+++ b/map/address_finder.cpp
@@ -460,7 +460,7 @@ search::AddressInfo Framework::GetAddressInfoAtPoint(m2::PointD const & pt) cons
 
   search::AddressInfo info;
 
-  search::ReverseGeocoder const coder(m_model.GetIndex());
+  search::ReverseGeocoder const coder(m_model.GetDataSource());
   search::ReverseGeocoder::Address addr;
   coder.GetNearbyAddress(pt, addr);
 
@@ -492,7 +492,7 @@ search::AddressInfo Framework::GetFeatureAddressInfo(FeatureType & ft) const
   // @TODO(vng): Temporarily commented - it's slow and not used in UI.
   //GetLocality(pt, info);
 
-  search::ReverseGeocoder const coder(m_model.GetIndex());
+  search::ReverseGeocoder const coder(m_model.GetDataSource());
   search::ReverseGeocoder::Address addr;
   if (coder.GetExactAddress(ft, addr))
   {
diff --git a/map/booking_availability_filter.cpp b/map/booking_availability_filter.cpp
index 352125a7bb..723c6630da 100644
--- a/map/booking_availability_filter.cpp
+++ b/map/booking_availability_filter.cpp
@@ -88,7 +88,7 @@ void FillResults(HotelToResults && hotelToResults, std::vector<std::string> cons
   }
 }
 
-void PrepareData(DataSourceBase const & index, search::Results const & results,
+void PrepareData(DataSourceBase const & dataSource, search::Results const & results,
                  HotelToResults & hotelToResults, availability::Cache & cache,
                  booking::AvailabilityParams & p)
 {
@@ -111,7 +111,7 @@ void PrepareData(DataSourceBase const & index, search::Results const & results,
   {
     if (mwmId != featureId.m_mwmId)
     {
-      guard = my::make_unique<LoaderGuard>(index, featureId.m_mwmId);
+      guard = my::make_unique<LoaderGuard>(dataSource, featureId.m_mwmId);
       mwmId = featureId.m_mwmId;
     }
 
@@ -164,7 +164,7 @@ void AvailabilityFilter::ApplyFilter(search::Results const & results,
   m_apiParams.m_hotelIds.clear();
 
   HotelToResults hotelToResults;
-  PrepareData(GetDelegate().GetIndex(), results, hotelToResults, *m_cache, m_apiParams);
+  PrepareData(GetDelegate().GetDataSource(), results, hotelToResults, *m_cache, m_apiParams);
 
   if (m_apiParams.m_hotelIds.empty())
   {
@@ -229,7 +229,7 @@ void AvailabilityFilter::GetFeaturesFromCache(search::Results const & results,
     if (mwmId != featureId.m_mwmId)
     {
       guard =
-          my::make_unique<LoaderGuard>(GetDelegate().GetIndex(), featureId.m_mwmId);
+          my::make_unique<LoaderGuard>(GetDelegate().GetDataSource(), featureId.m_mwmId);
       mwmId = featureId.m_mwmId;
     }
 
diff --git a/map/booking_filter.hpp b/map/booking_filter.hpp
index 0e45884238..bf4fbf71ba 100644
--- a/map/booking_filter.hpp
+++ b/map/booking_filter.hpp
@@ -28,7 +28,7 @@ public:
   public:
     virtual ~Delegate() = default;
 
-    virtual DataSourceBase const & GetIndex() const = 0;
+    virtual DataSourceBase const & GetDataSource() const = 0;
     virtual Api const & GetApi() const = 0;
   };
 
diff --git a/map/booking_filter_processor.cpp b/map/booking_filter_processor.cpp
index 09ca114e4b..22d1cf0f28 100644
--- a/map/booking_filter_processor.cpp
+++ b/map/booking_filter_processor.cpp
@@ -7,8 +7,8 @@ namespace booking
 {
 namespace filter
 {
-FilterProcessor::FilterProcessor(DataSourceBase const & index, booking::Api const & api)
-  : m_index(index)
+FilterProcessor::FilterProcessor(DataSourceBase const & dataSource, booking::Api const & api)
+  : m_dataSource(dataSource)
   , m_api(api)
 {
   m_filters.emplace(Type::Deals, std::make_unique<AvailabilityFilter>(*this));
@@ -60,9 +60,9 @@ void FilterProcessor::GetFeaturesFromCache(Types const & types, search::Results
   });
 }
 
-DataSourceBase const & FilterProcessor::GetIndex() const
+DataSourceBase const & FilterProcessor::GetDataSource() const
 {
-  return m_index;
+  return m_dataSource;
 }
 
 Api const & FilterProcessor::GetApi() const
diff --git a/map/booking_filter_processor.hpp b/map/booking_filter_processor.hpp
index 0017bdc0d0..0b0a91aa35 100644
--- a/map/booking_filter_processor.hpp
+++ b/map/booking_filter_processor.hpp
@@ -46,7 +46,7 @@ using FillSearchMarksCallback =
 class FilterProcessor : public FilterBase::Delegate
 {
 public:
-  FilterProcessor(DataSourceBase const & index, booking::Api const & api);
+  FilterProcessor(DataSourceBase const & dataSource, booking::Api const & api);
 
   void ApplyFilters(search::Results const & results, TasksInternal && tasks,
                     ApplicationMode const mode);
@@ -57,14 +57,14 @@ public:
                             FillSearchMarksCallback const & callback);
 
   // FilterInterface::Delegate overrides:
-  DataSourceBase const & GetIndex() const override;
+  DataSourceBase const & GetDataSource() const override;
   Api const & GetApi() const override;
 
 private:
   void ApplyConsecutively(search::Results const & results, TasksInternal & tasks);
   void ApplyIndependently(search::Results const & results, TasksInternal const & tasks);
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   Api const & m_api;
 
   std::unordered_map<Type, FilterPtr> m_filters;
diff --git a/map/discovery/discovery_manager.cpp b/map/discovery/discovery_manager.cpp
index 40965df746..35fb7a5f66 100644
--- a/map/discovery/discovery_manager.cpp
+++ b/map/discovery/discovery_manager.cpp
@@ -21,8 +21,8 @@ std::string GetQuery(discovery::ItemType const type)
 
 namespace discovery
 {
-Manager::Manager(DataSourceBase const & index, search::CityFinder & cityFinder, APIs const & apis)
-  : m_index(index)
+Manager::Manager(DataSourceBase const & dataSource, search::CityFinder & cityFinder, APIs const & apis)
+  : m_dataSource(dataSource)
   , m_cityFinder(cityFinder)
   , m_searchApi(apis.m_search)
   , m_viatorApi(apis.m_viator)
@@ -67,7 +67,7 @@ std::string Manager::GetCityViatorId(m2::PointD const & point) const
   if (!fid.IsValid())
     return {};
 
-  EditableDataSource::FeaturesLoaderGuard const guard(m_index, fid.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard const guard(m_dataSource, fid.m_mwmId);
   FeatureType ft;
   if (!guard.GetFeatureByIndex(fid.m_index, ft))
   {
diff --git a/map/discovery/discovery_manager.hpp b/map/discovery/discovery_manager.hpp
index 2565247267..c6010fda04 100644
--- a/map/discovery/discovery_manager.hpp
+++ b/map/discovery/discovery_manager.hpp
@@ -54,7 +54,7 @@ public:
 
   using ErrorCalback = std::function<void(uint32_t const requestId, ItemType const type)>;
 
-  Manager(DataSourceBase const & index, search::CityFinder & cityFinder, APIs const & apis);
+  Manager(DataSourceBase const & dataSource, search::CityFinder & cityFinder, APIs const & apis);
 
   template <typename ResultCallback>
   uint32_t Discover(Params && params, ResultCallback const & onResult, ErrorCalback const & onError)
@@ -153,7 +153,7 @@ private:
   static search::DiscoverySearchParams GetSearchParams(Manager::Params const & params, ItemType const type);
   std::string GetCityViatorId(m2::PointD const & point) const;
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   search::CityFinder & m_cityFinder;
   SearchAPI & m_searchApi;
   viator::Api const & m_viatorApi;
diff --git a/map/feature_vec_model.cpp b/map/feature_vec_model.cpp
index b6bbaa955b..d265a178a3 100644
--- a/map/feature_vec_model.cpp
+++ b/map/feature_vec_model.cpp
@@ -18,12 +18,12 @@ namespace model
 {
 FeaturesFetcher::FeaturesFetcher()
 {
-  m_multiIndex.AddObserver(*this);
+  m_dataSource.AddObserver(*this);
 }
 
 FeaturesFetcher::~FeaturesFetcher()
 {
-  m_multiIndex.RemoveObserver(*this);
+  m_dataSource.RemoveObserver(*this);
 }
 
 // While reading any files (classificator or mwm), there are 2 types of possible exceptions:
@@ -47,7 +47,7 @@ pair<MwmSet::MwmId, MwmSet::RegResult> FeaturesFetcher::RegisterMap(
 {
   try
   {
-    auto result = m_multiIndex.RegisterMap(localFile);
+    auto result = m_dataSource.RegisterMap(localFile);
     if (result.second != MwmSet::RegResult::Success)
     {
       LOG(LWARNING, ("Can't add map", localFile.GetCountryName(), "(", result.second, ").",
@@ -71,14 +71,14 @@ pair<MwmSet::MwmId, MwmSet::RegResult> FeaturesFetcher::RegisterMap(
 
 bool FeaturesFetcher::DeregisterMap(CountryFile const & countryFile)
 {
-  return m_multiIndex.Deregister(countryFile);
+  return m_dataSource.Deregister(countryFile);
 }
 
-void FeaturesFetcher::Clear() { m_multiIndex.Clear(); }
+void FeaturesFetcher::Clear() { m_dataSource.Clear(); }
 
 void FeaturesFetcher::ClearCaches()
 {
-  m_multiIndex.ClearCache();
+  m_dataSource.ClearCache();
 }
 
 void FeaturesFetcher::OnMapUpdated(platform::LocalCountryFile const & newFile,
diff --git a/map/feature_vec_model.hpp b/map/feature_vec_model.hpp
index a3b0b355d5..c3e397563d 100644
--- a/map/feature_vec_model.hpp
+++ b/map/feature_vec_model.hpp
@@ -31,7 +31,7 @@ class FeaturesFetcher : public MwmSet::Observer
   private:
     m2::RectD m_rect;
 
-    EditableDataSource m_multiIndex;
+    EditableDataSource m_dataSource;
 
     TMapDeregisteredCallback m_onMapDeregistered;
 
@@ -60,7 +60,7 @@ class FeaturesFetcher : public MwmSet::Observer
 
     inline bool IsLoaded(string const & countryFileName) const
     {
-      return m_multiIndex.IsLoaded(platform::CountryFile(countryFileName));
+      return m_dataSource.IsLoaded(platform::CountryFile(countryFileName));
     }
 
     // MwmSet::Observer overrides:
@@ -75,24 +75,24 @@ class FeaturesFetcher : public MwmSet::Observer
     void ForEachFeature(m2::RectD const & rect, std::function<void(FeatureType &)> const & fn,
                         int scale) const
     {
-      m_multiIndex.ForEachInRect(fn, rect, scale);
+      m_dataSource.ForEachInRect(fn, rect, scale);
     }
 
     void ForEachFeatureID(m2::RectD const & rect, std::function<void(FeatureID const &)> const & fn,
                           int scale) const
     {
-      m_multiIndex.ForEachFeatureIDInRect(fn, rect, scale);
+      m_dataSource.ForEachFeatureIDInRect(fn, rect, scale);
     }
 
     template <class ToDo>
     void ReadFeatures(ToDo & toDo, vector<FeatureID> const & features) const
     {
-      m_multiIndex.ReadFeatures(toDo, features);
+      m_dataSource.ReadFeatures(toDo, features);
     }
     //@}
 
-    DataSourceBase const & GetIndex() const { return m_multiIndex; }
-    DataSourceBase & GetIndex() { return m_multiIndex; }
+    DataSourceBase const & GetDataSource() const { return m_dataSource; }
+    DataSourceBase & GetDataSource() { return m_dataSource; }
     m2::RectD GetWorldRect() const;
   };
 }
diff --git a/map/framework.cpp b/map/framework.cpp
index 9f812536d1..a3b0124706 100644
--- a/map/framework.cpp
+++ b/map/framework.cpp
@@ -359,21 +359,21 @@ Framework::Framework(FrameworkParams const & params)
   , m_storage(platform::migrate::NeedMigrate() ? COUNTRIES_OBSOLETE_FILE : COUNTRIES_FILE)
   , m_enabledDiffs(params.m_enableDiffs)
   , m_isRenderingEnabled(true)
-  , m_transitManager(m_model.GetIndex(),
+  , m_transitManager(m_model.GetDataSource(),
                      [this](FeatureCallback const & fn, vector<FeatureID> const & features) {
                        return m_model.ReadFeatures(fn, features);
                      },
                      bind(&Framework::GetMwmsByRect, this, _1, false /* rough */))
   , m_routingManager(
         RoutingManager::Callbacks(
-            [this]() -> DataSourceBase & { return m_model.GetIndex(); },
+            [this]() -> DataSourceBase & { return m_model.GetDataSource(); },
             [this]() -> storage::CountryInfoGetter & { return GetCountryInfoGetter(); },
             [this](string const & id) -> string { return m_storage.GetParentIdFor(id); },
             [this]() -> StringsBundle const & { return m_stringsBundle; }),
         static_cast<RoutingManager::Delegate &>(*this))
   , m_trafficManager(bind(&Framework::GetMwmsByRect, this, _1, false /* rough */),
                      kMaxTrafficCacheSizeBytes, m_routingManager.RoutingSession())
-  , m_bookingFilterProcessor(m_model.GetIndex(), *m_bookingApi)
+  , m_bookingFilterProcessor(m_model.GetDataSource(), *m_bookingApi)
   , m_displacementModeManager([this](bool show) {
     int const mode = show ? dp::displacement::kHotelMode : dp::displacement::kDefaultMode;
     if (m_drapeEngine != nullptr)
@@ -473,11 +473,11 @@ Framework::Framework(FrameworkParams const & params)
 
   osm::Editor & editor = osm::Editor::Instance();
 
-  editor.SetDelegate(make_unique<search::EditorDelegate>(m_model.GetIndex()));
+  editor.SetDelegate(make_unique<search::EditorDelegate>(m_model.GetDataSource()));
   editor.SetInvalidateFn([this](){ InvalidateRect(GetCurrentViewport()); });
   editor.LoadEdits();
 
-  m_model.GetIndex().AddObserver(editor);
+  m_model.GetDataSource().AddObserver(editor);
 
   LOG(LINFO, ("Editor initialized"));
 
@@ -622,7 +622,7 @@ void Framework::OnMapDeregistered(platform::LocalCountryFile const & localFile)
   else
     GetPlatform().RunTask(Platform::Thread::Gui, action);
 
-  auto const mwmId = m_model.GetIndex().GetMwmIdByCountryFile(localFile.GetCountryFile());
+  auto const mwmId = m_model.GetDataSource().GetMwmIdByCountryFile(localFile.GetCountryFile());
   m_trafficManager.OnMwmDeregistered(mwmId);
   m_transitManager.OnMwmDeregistered(mwmId);
 }
@@ -636,7 +636,7 @@ bool Framework::HasUnsavedEdits(storage::TCountryId const & countryId)
     if (groupNode)
       return;
     hasUnsavedChanges |= osm::Editor::Instance().HaveMapEditsToUpload(
-          m_model.GetIndex().GetMwmIdByCountryFile(platform::CountryFile(fileName)));
+          m_model.GetDataSource().GetMwmIdByCountryFile(platform::CountryFile(fileName)));
   };
   GetStorage().ForEachInSubtree(countryId, forEachInSubtree);
   return hasUnsavedChanges;
@@ -744,7 +744,7 @@ void Framework::FillFeatureInfo(FeatureID const & fid, place_page::Info & info)
     return;
   }
 
-  EditableDataSource::FeaturesLoaderGuard const guard(m_model.GetIndex(), fid.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard const guard(m_model.GetDataSource(), fid.m_mwmId);
   FeatureType ft;
   if (!guard.GetFeatureByIndex(fid.m_index, ft))
   {
@@ -1324,7 +1324,7 @@ void Framework::InitUGC()
 {
   ASSERT(!m_ugcApi.get(), ("InitUGC() must be called only once."));
 
-  m_ugcApi = make_unique<ugc::Api>(m_model.GetIndex(), [this](size_t numberOfUnsynchronized) {
+  m_ugcApi = make_unique<ugc::Api>(m_model.GetDataSource(), [this](size_t numberOfUnsynchronized) {
     if (numberOfUnsynchronized == 0)
       return;
 
@@ -1341,7 +1341,7 @@ void Framework::InitSearchAPI()
   try
   {
     m_searchAPI =
-        make_unique<SearchAPI>(m_model.GetIndex(), m_storage, *m_infoGetter,
+        make_unique<SearchAPI>(m_model.GetDataSource(), m_storage, *m_infoGetter,
                                static_cast<SearchAPI::Delegate &>(*this));
   }
   catch (RootException const & e)
@@ -1357,7 +1357,7 @@ void Framework::InitDiscoveryManager()
 
   discovery::Manager::APIs const apis(*m_searchAPI.get(), *m_viatorApi.get(), *m_localsApi.get());
   m_discoveryManager =
-      make_unique<discovery::Manager>(m_model.GetIndex(), *m_cityFinder.get(), apis);
+      make_unique<discovery::Manager>(m_model.GetDataSource(), *m_cityFinder.get(), apis);
 }
 
 void Framework::InitTransliteration()
@@ -2043,7 +2043,7 @@ unique_ptr<FeatureType> Framework::GetFeatureAtPoint(m2::PointD const & mercator
 {
   unique_ptr<FeatureType> poi, line, area;
   uint32_t const coastlineType = classif().GetCoastType();
-  indexer::ForEachFeatureAtPoint(m_model.GetIndex(), [&, coastlineType](FeatureType & ft)
+  indexer::ForEachFeatureAtPoint(m_model.GetDataSource(), [&, coastlineType](FeatureType & ft)
   {
     // TODO @alexz
     // remove manual parsing after refactoring with usermarks'll be finished
@@ -2077,7 +2077,7 @@ bool Framework::GetFeatureByID(FeatureID const & fid, FeatureType & ft) const
 {
   ASSERT(fid.IsValid(), ());
 
-  EditableDataSource::FeaturesLoaderGuard guard(m_model.GetIndex(), fid.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard guard(m_model.GetDataSource(), fid.m_mwmId);
   if (!guard.GetFeatureByIndex(fid.m_index, ft))
     return false;
 
@@ -2598,7 +2598,7 @@ vector<m2::TriangleD> Framework::GetSelectedFeatureTriangles() const
   if (!m_selectedFeature.IsValid())
     return triangles;
 
-  EditableDataSource::FeaturesLoaderGuard const guard(m_model.GetIndex(), m_selectedFeature.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard const guard(m_model.GetDataSource(), m_selectedFeature.m_mwmId);
   FeatureType ft;
   if (!guard.GetFeatureByIndex(m_selectedFeature.m_index, ft))
     return triangles;
@@ -2732,10 +2732,10 @@ bool Framework::ParseEditorDebugCommand(search::SearchParams const & params)
 
 namespace
 {
-WARN_UNUSED_RESULT bool LocalizeStreet(DataSourceBase const & index, FeatureID const & fid,
+WARN_UNUSED_RESULT bool LocalizeStreet(DataSourceBase const & dataSource, FeatureID const & fid,
                                        osm::LocalizedStreet & result)
 {
-  EditableDataSource::FeaturesLoaderGuard g(index, fid.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard g(dataSource, fid.m_mwmId);
   FeatureType ft;
   if (!g.GetFeatureByIndex(fid.m_index, ft))
     return false;
@@ -2748,7 +2748,7 @@ WARN_UNUSED_RESULT bool LocalizeStreet(DataSourceBase const & index, FeatureID c
 }
 
 vector<osm::LocalizedStreet> TakeSomeStreetsAndLocalize(
-    vector<search::ReverseGeocoder::Street> const & streets, DataSourceBase const & index)
+    vector<search::ReverseGeocoder::Street> const & streets, DataSourceBase const & dataSource)
 
 {
   vector<osm::LocalizedStreet> results;
@@ -2767,7 +2767,7 @@ vector<osm::LocalizedStreet> TakeSomeStreetsAndLocalize(
       continue;
 
     osm::LocalizedStreet ls;
-    if (!LocalizeStreet(index, street.m_id, ls))
+    if (!LocalizeStreet(dataSource, street.m_id, ls))
       continue;
 
     results.emplace_back(move(ls));
@@ -2777,7 +2777,7 @@ vector<osm::LocalizedStreet> TakeSomeStreetsAndLocalize(
   return results;
 }
 
-void SetStreet(search::ReverseGeocoder const & coder, DataSourceBase const & index,
+void SetStreet(search::ReverseGeocoder const & coder, DataSourceBase const & dataSource,
                FeatureType & ft, osm::EditableMapObject & emo)
 {
   auto const & editor = osm::Editor::Instance();
@@ -2802,7 +2802,7 @@ void SetStreet(search::ReverseGeocoder const & coder, DataSourceBase const & ind
   if (!featureIsInEditor && featureHasStreetInMwm)
     street = streetsPool[featureStreetIndex].m_name;
 
-  auto localizedStreets = TakeSomeStreetsAndLocalize(streetsPool, index);
+  auto localizedStreets = TakeSomeStreetsAndLocalize(streetsPool, dataSource);
 
   if (!street.empty())
   {
@@ -2815,7 +2815,7 @@ void SetStreet(search::ReverseGeocoder const & coder, DataSourceBase const & ind
     if (it != end(streetsPool))
     {
       osm::LocalizedStreet ls;
-      if (!LocalizeStreet(index, it->m_id, ls))
+      if (!LocalizeStreet(dataSource, it->m_id, ls))
         ls.m_defaultName = street;
 
       emo.SetStreet(ls);
@@ -2844,7 +2844,7 @@ void SetStreet(search::ReverseGeocoder const & coder, DataSourceBase const & ind
   emo.SetNearbyStreets(move(localizedStreets));
 }
 
-void SetHostingBuildingAddress(FeatureID const & hostingBuildingFid, DataSourceBase const & index,
+void SetHostingBuildingAddress(FeatureID const & hostingBuildingFid, DataSourceBase const & dataSource,
                                search::ReverseGeocoder const & coder, osm::EditableMapObject & emo)
 {
   if (!hostingBuildingFid.IsValid())
@@ -2852,7 +2852,7 @@ void SetHostingBuildingAddress(FeatureID const & hostingBuildingFid, DataSourceB
 
   FeatureType hostingBuildingFeature;
 
-  EditableDataSource::FeaturesLoaderGuard g(index, hostingBuildingFid.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard g(dataSource, hostingBuildingFid.m_mwmId);
   if (!g.GetFeatureByIndex(hostingBuildingFid.m_index, hostingBuildingFeature))
     return;
 
@@ -2877,22 +2877,22 @@ bool Framework::CreateMapObject(m2::PointD const & mercator, uint32_t const feat
                                 osm::EditableMapObject & emo) const
 {
   emo = {};
-  auto const & index = m_model.GetIndex();
-  MwmSet::MwmId const mwmId = index.GetMwmIdByCountryFile(
+  auto const & dataSource = m_model.GetDataSource();
+  MwmSet::MwmId const mwmId = dataSource.GetMwmIdByCountryFile(
         platform::CountryFile(m_infoGetter->GetRegionCountryId(mercator)));
   if (!mwmId.IsAlive())
     return false;
 
   GetPlatform().GetMarketingService().SendMarketingEvent(marketing::kEditorAddStart, {});
 
-  search::ReverseGeocoder const coder(m_model.GetIndex());
+  search::ReverseGeocoder const coder(m_model.GetDataSource());
   vector<search::ReverseGeocoder::Street> streets;
 
   coder.GetNearbyStreets(mwmId, mercator, streets);
-  emo.SetNearbyStreets(TakeSomeStreetsAndLocalize(streets, m_model.GetIndex()));
+  emo.SetNearbyStreets(TakeSomeStreetsAndLocalize(streets, m_model.GetDataSource()));
 
   // TODO(mgsergio): Check emo is a poi. For now it is the only option.
-  SetHostingBuildingAddress(FindBuildingAtPoint(mercator), index, coder, emo);
+  SetHostingBuildingAddress(FindBuildingAtPoint(mercator), dataSource, coder, emo);
 
   return osm::Editor::Instance().CreatePoint(featureType, mercator, mwmId, emo);
 }
@@ -2914,15 +2914,15 @@ bool Framework::GetEditableMapObject(FeatureID const & fid, osm::EditableMapObje
   auto const & editor = osm::Editor::Instance();
   emo.SetEditableProperties(editor.GetEditableProperties(ft));
 
-  auto const & index = m_model.GetIndex();
-  search::ReverseGeocoder const coder(index);
-  SetStreet(coder, index, ft, emo);
+  auto const & dataSource = m_model.GetDataSource();
+  search::ReverseGeocoder const coder(dataSource);
+  SetStreet(coder, dataSource, ft, emo);
 
   if (!ftypes::IsBuildingChecker::Instance()(ft) &&
       (emo.GetHouseNumber().empty() || emo.GetStreet().m_defaultName.empty()))
   {
     SetHostingBuildingAddress(FindBuildingAtPoint(feature::GetCenter(ft)),
-                              index, coder, emo);
+                              dataSource, coder, emo);
   }
 
   return true;
@@ -2946,7 +2946,7 @@ osm::Editor::SaveResult Framework::SaveEditedMapObject(osm::EditableMapObject em
   {
     auto const isCreatedFeature = editor.IsCreatedFeature(emo.GetID());
 
-    EditableDataSource::FeaturesLoaderGuard g(m_model.GetIndex(), emo.GetID().m_mwmId);
+    EditableDataSource::FeaturesLoaderGuard g(m_model.GetDataSource(), emo.GetID().m_mwmId);
     FeatureType originalFeature;
     if (!isCreatedFeature)
     {
@@ -2974,7 +2974,7 @@ osm::Editor::SaveResult Framework::SaveEditedMapObject(osm::EditableMapObject em
     issueLatLon = MercatorBounds::ToLatLon(feature::GetCenter(hostingBuildingFeature));
 
     search::ReverseGeocoder::Address hostingBuildingAddress;
-    search::ReverseGeocoder const coder(m_model.GetIndex());
+    search::ReverseGeocoder const coder(m_model.GetDataSource());
     // The is no address to take from a hosting building. Fallback to simple saving.
     if (!coder.GetExactAddress(hostingBuildingFeature, hostingBuildingAddress))
       break;
@@ -3274,7 +3274,7 @@ vector<MwmSet::MwmId> Framework::GetMwmsByRect(m2::RectD const & rect, bool roug
 
 MwmSet::MwmId Framework::GetMwmIdByName(string const & name) const
 {
-  return m_model.GetIndex().GetMwmIdByCountryFile(platform::CountryFile(name));
+  return m_model.GetDataSource().GetMwmIdByCountryFile(platform::CountryFile(name));
 }
 
 void Framework::ReadFeatures(function<void(FeatureType const &)> const & reader,
@@ -3316,7 +3316,7 @@ void Framework::InitCityFinder()
 {
   ASSERT(!m_cityFinder, ());
 
-  m_cityFinder = make_unique<search::CityFinder>(m_model.GetIndex());
+  m_cityFinder = make_unique<search::CityFinder>(m_model.GetDataSource());
 }
 
 void Framework::InitTaxiEngine()
@@ -3357,7 +3357,7 @@ void Framework::InjectViator(place_page::Info & info)
     return;
 
   auto const & country = GetStorage().CountryByCountryId(info.GetCountryId());
-  auto const mwmId = m_model.GetIndex().GetMwmIdByCountryFile(country.GetFile());
+  auto const mwmId = m_model.GetDataSource().GetMwmIdByCountryFile(country.GetFile());
 
   if (!mwmId.IsAlive() || !mwmId.GetInfo()->IsRegistered())
     return;
@@ -3367,7 +3367,7 @@ void Framework::InjectViator(place_page::Info & info)
   static double constexpr kSearchRadiusM = 3.0;
   m2::RectD const rect = MercatorBounds::RectByCenterXYAndSizeInMeters(point, kSearchRadiusM);
 
-  m_model.GetIndex().ForEachInRectForMWM(
+  m_model.GetDataSource().ForEachInRectForMWM(
       [&info](FeatureType & ft) {
         if (ft.GetFeatureType() != feature::EGeomType::GEOM_POINT || info.IsSponsored() ||
             !ftypes::IsViatorChecker::Instance()(ft))
diff --git a/map/framework.hpp b/map/framework.hpp
index 7b081c5ce4..662a1ce512 100644
--- a/map/framework.hpp
+++ b/map/framework.hpp
@@ -311,7 +311,7 @@ public:
   storage::CountryInfoGetter & GetCountryInfoGetter() { return *m_infoGetter; }
   StorageDownloadingPolicy & GetDownloadingPolicy() { return m_storageDownloadingPolicy; }
 
-  DataSourceBase const & GetIndex() const { return m_model.GetIndex(); }
+  DataSourceBase const & GetDataSource() const { return m_model.GetDataSource(); }
 
   SearchAPI & GetSearchAPI();
   SearchAPI const & GetSearchAPI() const;
@@ -679,7 +679,7 @@ public:
   template <typename TFn>
   void ForEachFeatureAtPoint(TFn && fn, m2::PointD const & mercator) const
   {
-    indexer::ForEachFeatureAtPoint(m_model.GetIndex(), fn, mercator, 0.0);
+    indexer::ForEachFeatureAtPoint(m_model.GetDataSource(), fn, mercator, 0.0);
   }
   /// Set parse to false if you don't need all feature fields ready.
   /// TODO(AlexZ): Refactor code which uses this method to get rid of it.
diff --git a/map/map_integration_tests/interactive_search_test.cpp b/map/map_integration_tests/interactive_search_test.cpp
index 5803383dc2..ebcda503bf 100644
--- a/map/map_integration_tests/interactive_search_test.cpp
+++ b/map/map_integration_tests/interactive_search_test.cpp
@@ -118,7 +118,7 @@ UNIT_CLASS_TEST(InteractiveSearchTest, Smoke)
 
     TEST(!stats.m_hotelDisplacementModeSet, ());
     TEST_EQUAL(stats.m_numShownResults, 4, ());
-    TEST(MatchResults(m_index, rules, request.Results()), ());
+    TEST(MatchResults(m_dataSource, rules, request.Results()), ());
   }
 
   {
@@ -132,7 +132,7 @@ UNIT_CLASS_TEST(InteractiveSearchTest, Smoke)
 
     TEST(stats.m_hotelDisplacementModeSet, ());
     TEST_EQUAL(stats.m_numShownResults, 4, ());
-    TEST(MatchResults(m_index, rules, request.Results()), ());
+    TEST(MatchResults(m_dataSource, rules, request.Results()), ());
   }
 }
 
@@ -161,7 +161,7 @@ UNIT_CLASS_TEST(InteractiveSearchTest, NearbyFeaturesInViewport)
     TestSearchRequest request(m_engine, params);
     request.Run();
 
-    TEST(MatchResults(m_index,
+    TEST(MatchResults(m_dataSource,
                       TRules{ExactMatch(id, cafe1), ExactMatch(id, cafe2), ExactMatch(id, cafe3)},
                       request.Results()),
          ());
@@ -175,8 +175,8 @@ UNIT_CLASS_TEST(InteractiveSearchTest, NearbyFeaturesInViewport)
 
     auto const & results = request.Results();
 
-    TEST(MatchResults(m_index, TRules{ExactMatch(id, cafe1), ExactMatch(id, cafe3)}, results) ||
-             MatchResults(m_index, TRules{ExactMatch(id, cafe2)}, results),
+    TEST(MatchResults(m_dataSource, TRules{ExactMatch(id, cafe1), ExactMatch(id, cafe3)}, results) ||
+             MatchResults(m_dataSource, TRules{ExactMatch(id, cafe2)}, results),
          ());
   }
 }
diff --git a/map/map_tests/address_tests.cpp b/map/map_tests/address_tests.cpp
index 2a12cc5691..2b54ef1fba 100644
--- a/map/map_tests/address_tests.cpp
+++ b/map/map_tests/address_tests.cpp
@@ -33,10 +33,10 @@ UNIT_TEST(ReverseGeocoder_Smoke)
 
   LocalCountryFile file = LocalCountryFile::MakeForTesting("minsk-pass");
 
-  DataSource index;
-  TEST_EQUAL(index.RegisterMap(file).second, MwmSet::RegResult::Success, ());
+  DataSource dataSource;
+  TEST_EQUAL(dataSource.RegisterMap(file).second, MwmSet::RegResult::Success, ());
 
-  ReverseGeocoder coder(index);
+  ReverseGeocoder coder(dataSource);
 
   TestAddress(coder, {53.89815, 27.54265}, "улицамясникова", "32");
   TestAddress(coder, {53.89953, 27.54189}, "улицанемига", "42");
diff --git a/map/map_tests/booking_filter_test.cpp b/map/map_tests/booking_filter_test.cpp
index 23819d1c4b..4c4aa7bb0d 100644
--- a/map/map_tests/booking_filter_test.cpp
+++ b/map/map_tests/booking_filter_test.cpp
@@ -29,7 +29,7 @@ class TestMwmEnvironment : public TestWithCustomMwms,
                            public FilterBase::Delegate
 {
 public:
-  DataSourceBase const & GetIndex() const override { return m_index; }
+  DataSourceBase const & GetDataSource() const override { return m_dataSource; }
 
   booking::Api const & GetApi() const override { return m_api; }
 
@@ -85,7 +85,7 @@ UNIT_CLASS_TEST(TestMwmEnvironment, BookingFilter_AvailabilitySmoke)
   search::Results results;
   results.AddResult({"suggest for testing", "suggest for testing"});
   search::Results expectedResults;
-  m_index.ForEachInRect(
+  m_dataSource.ForEachInRect(
       [&results, &expectedResults](FeatureType & ft) {
         search::Result::Metadata metadata;
         metadata.m_isSponsoredHotel = true;
@@ -158,7 +158,7 @@ UNIT_CLASS_TEST(TestMwmEnvironment, BookingFilter_ProcessorSmoke)
   search::Results expectedAvailabilityResults;
   search::Results expectedDealsResults;
   search::Results expectedAvailableWithDeals;
-  m_index.ForEachInRect(
+  m_dataSource.ForEachInRect(
     [&](FeatureType & ft) {
       search::Result::Metadata metadata;
       metadata.m_isSponsoredHotel = true;
@@ -202,7 +202,7 @@ UNIT_CLASS_TEST(TestMwmEnvironment, BookingFilter_ProcessorSmoke)
 
   tasks.emplace_back(Type::Deals, std::move(dealsParams));
 
-  FilterProcessor processor(GetIndex(), GetApi());
+  FilterProcessor processor(GetDataSource(), GetApi());
   auto tasksCopy = tasks;
   processor.ApplyFilters(results, std::move(tasksCopy), ApplicationMode::Independent);
 
diff --git a/map/map_tests/mwm_set_test.cpp b/map/map_tests/mwm_set_test.cpp
index b46bc51c99..436d560949 100644
--- a/map/map_tests/mwm_set_test.cpp
+++ b/map/map_tests/mwm_set_test.cpp
@@ -41,20 +41,20 @@ UNIT_TEST(MwmSet_FileSystemErrors)
   };
   MY_SCOPE_GUARD(restoreGuard, restoreFn);
 
-  DataSource index;
-  auto p = index.RegisterMap(localFile);
+  DataSource dataSource;
+  auto p = dataSource.RegisterMap(localFile);
   TEST_EQUAL(p.second, DataSource::RegResult::Success, ());
 
   // Registering should pass ok.
-  TEST(index.GetMwmIdByCountryFile(file) != DataSource::MwmId(), ());
+  TEST(dataSource.GetMwmIdByCountryFile(file) != DataSource::MwmId(), ());
 
   // Getting handle causes feature offsets index building which should fail
   // because of write permissions.
-  TEST(!index.GetMwmHandleById(p.first).IsAlive(), ());
+  TEST(!dataSource.GetMwmHandleById(p.first).IsAlive(), ());
 
   // Map is automatically deregistered after the fail.
   vector<shared_ptr<MwmInfo>> infos;
-  index.GetMwmsInfo(infos);
+  dataSource.GetMwmsInfo(infos);
   TEST(infos.empty(), ());
 }
 #endif
diff --git a/map/map_tests/search_api_tests.cpp b/map/map_tests/search_api_tests.cpp
index b21fad01f5..802379f440 100644
--- a/map/map_tests/search_api_tests.cpp
+++ b/map/map_tests/search_api_tests.cpp
@@ -61,7 +61,7 @@ class SearchAPITest : public generator::tests_support::TestWithCustomMwms
 public:
   SearchAPITest()
     : m_infoGetter(CountryInfoReader::CreateCountryInfoReader(GetPlatform()))
-    , m_api(m_index, m_storage, *m_infoGetter, m_delegate)
+    , m_api(m_dataSource, m_storage, *m_infoGetter, m_delegate)
   {
   }
 
@@ -107,7 +107,7 @@ UNIT_CLASS_TEST(SearchAPITest, MultipleViewportsRequests)
     if (stage == 0)
     {
       Rules const rules = {ExactMatch(id, cafe1), ExactMatch(id, cafe2)};
-      TEST(MatchResults(m_index, rules, results), ());
+      TEST(MatchResults(m_dataSource, rules, results), ());
 
       promise0.set_value();
     }
@@ -115,7 +115,7 @@ UNIT_CLASS_TEST(SearchAPITest, MultipleViewportsRequests)
     {
       TEST_EQUAL(stage, 1, ());
       Rules const rules = {ExactMatch(id, cafe3), ExactMatch(id, cafe4)};
-      TEST(MatchResults(m_index, rules, results), ());
+      TEST(MatchResults(m_dataSource, rules, results), ());
 
       promise1.set_value();
     }
diff --git a/map/routing_manager.cpp b/map/routing_manager.cpp
index 6ee463daf2..ab60aa2e09 100644
--- a/map/routing_manager.cpp
+++ b/map/routing_manager.cpp
@@ -364,8 +364,8 @@ RouterType RoutingManager::GetLastUsedRouter() const
 
 void RoutingManager::SetRouterImpl(RouterType type)
 {
-  auto const indexGetterFn = m_callbacks.m_indexGetter;
-  CHECK(indexGetterFn, ("Type:", type));
+  auto const dataSourceGetterFn = m_callbacks.m_dataSourceGetter;
+  CHECK(dataSourceGetterFn, ("Type:", type));
 
   VehicleType const vehicleType = GetVehicleType(type);
 
@@ -380,10 +380,10 @@ void RoutingManager::SetRouterImpl(RouterType type)
   auto numMwmIds = make_shared<NumMwmIds>();
   m_delegate.RegisterCountryFilesOnRoute(numMwmIds);
 
-  auto & index = m_callbacks.m_indexGetter();
+  auto & dataSource = m_callbacks.m_dataSourceGetter();
 
   auto localFileChecker = [this](string const & countryFile) -> bool {
-    MwmSet::MwmId const mwmId = m_callbacks.m_indexGetter().GetMwmIdByCountryFile(
+    MwmSet::MwmId const mwmId = m_callbacks.m_dataSourceGetter().GetMwmIdByCountryFile(
       platform::CountryFile(countryFile));
     if (!mwmId.IsAlive())
       return false;
@@ -399,7 +399,7 @@ void RoutingManager::SetRouterImpl(RouterType type)
   auto router = make_unique<IndexRouter>(vehicleType, m_loadAltitudes, m_callbacks.m_countryParentNameGetterFn,
                                          countryFileGetter, getMwmRectByName, numMwmIds,
                                          MakeNumMwmTree(*numMwmIds, m_callbacks.m_countryInfoGetter()),
-                                         m_routingSession, index);
+                                         m_routingSession, dataSource);
 
   m_routingSession.SetRoutingSettings(GetRoutingSettings(vehicleType));
   m_routingSession.SetRouter(move(router), move(fetcher));
@@ -455,7 +455,7 @@ void RoutingManager::InsertRoute(Route const & route)
     m_delegate.RegisterCountryFilesOnRoute(numMwmIds);
     auto getMwmId = [this, numMwmIds](routing::NumMwmId numMwmId)
     {
-      return m_callbacks.m_indexGetter().GetMwmIdByCountryFile(numMwmIds->GetFile(numMwmId));
+      return m_callbacks.m_dataSourceGetter().GetMwmIdByCountryFile(numMwmIds->GetFile(numMwmId));
     };
     transitRouteDisplay = make_shared<TransitRouteDisplay>(*m_transitReadManager, getMwmId,
                                                            m_callbacks.m_stringsBundleGetter,
@@ -904,10 +904,10 @@ void RoutingManager::CheckLocationForRouting(location::GpsInfo const & info)
   if (!IsRoutingActive())
     return;
 
-  auto const featureIndexGetterFn = m_callbacks.m_indexGetter;
-  ASSERT(featureIndexGetterFn, ());
+  auto const featureDataSourceGetterFn = m_callbacks.m_dataSourceGetter;
+  ASSERT(featureDataSourceGetterFn, ());
   RoutingSession::State const state =
-      m_routingSession.OnLocationPositionChanged(info, featureIndexGetterFn());
+      m_routingSession.OnLocationPositionChanged(info, featureDataSourceGetterFn());
   if (state == RoutingSession::RouteNeedRebuild)
   {
     m_routingSession.RebuildRoute(
diff --git a/map/routing_manager.hpp b/map/routing_manager.hpp
index da3b5b9bf7..5e6ed26bca 100644
--- a/map/routing_manager.hpp
+++ b/map/routing_manager.hpp
@@ -67,22 +67,24 @@ public:
 
   struct Callbacks
   {
-    using IndexGetterFn = std::function<DataSourceBase &()>;
+    using DataSourceGetterFn = std::function<DataSourceBase &()>;
     using CountryInfoGetterFn = std::function<storage::CountryInfoGetter &()>;
     using CountryParentNameGetterFn = std::function<std::string(std::string const &)>;
     using GetStringsBundleFn = std::function<StringsBundle const &()>;
 
-    template <typename IndexGetter, typename CountryInfoGetter, typename CountryParentNameGetter,
-        typename StringsBundleGetter>
-    Callbacks(IndexGetter && featureIndexGetter, CountryInfoGetter && countryInfoGetter,
-              CountryParentNameGetter && countryParentNameGetter, StringsBundleGetter && stringsBundleGetter)
-      : m_indexGetter(std::forward<IndexGetter>(featureIndexGetter))
+    template <typename DataSourceGetter, typename CountryInfoGetter,
+              typename CountryParentNameGetter, typename StringsBundleGetter>
+    Callbacks(DataSourceGetter && dataSourceGetter, CountryInfoGetter && countryInfoGetter,
+              CountryParentNameGetter && countryParentNameGetter,
+              StringsBundleGetter && stringsBundleGetter)
+      : m_dataSourceGetter(std::forward<DataSourceGetter>(dataSourceGetter))
       , m_countryInfoGetter(std::forward<CountryInfoGetter>(countryInfoGetter))
       , m_countryParentNameGetterFn(std::forward<CountryParentNameGetter>(countryParentNameGetter))
       , m_stringsBundleGetter(std::forward<StringsBundleGetter>(stringsBundleGetter))
-    {}
+    {
+    }
 
-    IndexGetterFn m_indexGetter;
+    DataSourceGetterFn m_dataSourceGetter;
     CountryInfoGetterFn m_countryInfoGetter;
     CountryParentNameGetterFn m_countryParentNameGetterFn;
     GetStringsBundleFn m_stringsBundleGetter;
diff --git a/map/search_api.cpp b/map/search_api.cpp
index f70e1b7fb5..6a8a41667b 100644
--- a/map/search_api.cpp
+++ b/map/search_api.cpp
@@ -116,13 +116,13 @@ private:
 };
 }  // namespace
 
-SearchAPI::SearchAPI(DataSourceBase & index, storage::Storage const & storage,
+SearchAPI::SearchAPI(DataSourceBase & dataSource, storage::Storage const & storage,
                      storage::CountryInfoGetter const & infoGetter, Delegate & delegate)
-  : m_index(index)
+  : m_dataSource(dataSource)
   , m_storage(storage)
   , m_infoGetter(infoGetter)
   , m_delegate(delegate)
-  , m_engine(m_index, GetDefaultCategories(), m_infoGetter,
+  , m_engine(m_dataSource, GetDefaultCategories(), m_infoGetter,
              Engine::Params(languages::GetCurrentTwine() /* locale */, 1 /* params.m_numThreads */))
 {
 }
@@ -260,7 +260,7 @@ bool SearchAPI::SearchInDownloader(storage::DownloaderSearchParams const & param
   p.m_needHighlighting = false;
 
   p.m_onResults = DownloaderSearchCallback(static_cast<DownloaderSearchCallback::Delegate &>(*this),
-                                           m_index, m_infoGetter, m_storage, params);
+                                           m_dataSource, m_infoGetter, m_storage, params);
 
   return Search(p, true /* forceSearch */);
 }
diff --git a/map/search_api.hpp b/map/search_api.hpp
index f06c5c234f..257bad307f 100644
--- a/map/search_api.hpp
+++ b/map/search_api.hpp
@@ -87,7 +87,7 @@ public:
     virtual search::ProductInfo GetProductInfo(search::Result const & result) const { return {}; };
   };
 
-  SearchAPI(DataSourceBase & index, storage::Storage const & storage,
+  SearchAPI(DataSourceBase & dataSource, storage::Storage const & storage,
             storage::CountryInfoGetter const & infoGetter, Delegate & delegate);
   virtual ~SearchAPI() = default;
 
@@ -155,7 +155,7 @@ private:
   bool QueryMayBeSkipped(search::SearchParams const & prevParams,
                          search::SearchParams const & currParams) const;
 
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   storage::Storage const & m_storage;
   storage::CountryInfoGetter const & m_infoGetter;
   Delegate & m_delegate;
diff --git a/map/transit/transit_reader.cpp b/map/transit/transit_reader.cpp
index 9f77102c0c..393c733e4a 100644
--- a/map/transit/transit_reader.cpp
+++ b/map/transit/transit_reader.cpp
@@ -58,7 +58,7 @@ void ReadTransitTask::Init(uint64_t id, MwmSet::MwmId const & mwmId,
 
 void ReadTransitTask::Do()
 {
-  MwmSet::MwmHandle handle = m_index.GetMwmHandleById(m_mwmId);
+  MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleById(m_mwmId);
   if (!handle.IsAlive())
   {
     // It's possible that mwm handle is not alive because mwm may be removed after
@@ -137,9 +137,9 @@ unique_ptr<TransitDisplayInfo> && ReadTransitTask::GetTransitInfo()
   return move(m_transitInfo);
 }
 
-TransitReadManager::TransitReadManager(DataSourceBase & index, TReadFeaturesFn const & readFeaturesFn,
+TransitReadManager::TransitReadManager(DataSourceBase & dataSource, TReadFeaturesFn const & readFeaturesFn,
                                        GetMwmsByRectFn const & getMwmsByRectFn)
-  : m_index(index)
+  : m_dataSource(dataSource)
   , m_readFeaturesFn(readFeaturesFn)
   , m_getMwmsByRectFn(getMwmsByRectFn)
 {
@@ -303,7 +303,7 @@ bool TransitReadManager::GetTransitDisplayInfo(TransitDisplayInfos & transitDisp
   for (auto & mwmTransitPair : transitDisplayInfos)
   {
     auto const & mwmId = mwmTransitPair.first;
-    auto task = my::make_unique<ReadTransitTask>(m_index, m_readFeaturesFn);
+    auto task = my::make_unique<ReadTransitTask>(m_dataSource, m_readFeaturesFn);
     task->Init(groupId, mwmId, move(mwmTransitPair.second));
     transitTasks[mwmId] = move(task);
   }
diff --git a/map/transit/transit_reader.hpp b/map/transit/transit_reader.hpp
index 3eaabb7e42..5644763b58 100644
--- a/map/transit/transit_reader.hpp
+++ b/map/transit/transit_reader.hpp
@@ -31,9 +31,9 @@ using TReadFeaturesFn = std::function<void (FeatureCallback const & , std::vecto
 class ReadTransitTask: public threads::IRoutine
 {
 public:
-  ReadTransitTask(DataSourceBase & index,
+  ReadTransitTask(DataSourceBase & dataSource,
                   TReadFeaturesFn const & readFeaturesFn)
-    : m_index(index), m_readFeaturesFn(readFeaturesFn)
+    : m_dataSource(dataSource), m_readFeaturesFn(readFeaturesFn)
   {}
 
   void Init(uint64_t id, MwmSet::MwmId const & mwmId,
@@ -65,7 +65,7 @@ private:
     }
   };
 
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   TReadFeaturesFn m_readFeaturesFn;
 
   uint64_t m_id = 0;
@@ -83,7 +83,7 @@ public:
   using GetMwmsByRectFn = function<vector<MwmSet::MwmId>(m2::RectD const &)>;
 
 
-  TransitReadManager(DataSourceBase & index, TReadFeaturesFn const & readFeaturesFn,
+  TransitReadManager(DataSourceBase & dataSource, TReadFeaturesFn const & readFeaturesFn,
                      GetMwmsByRectFn const & getMwmsByRectFn);
   ~TransitReadManager();
 
@@ -113,7 +113,7 @@ private:
   uint64_t m_nextTasksGroupId = 0;
   std::map<uint64_t, size_t> m_tasksGroups;
 
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   TReadFeaturesFn m_readFeaturesFn;
 
   df::DrapeEngineSafePtr m_drapeEngine;
diff --git a/openlr/candidate_points_getter.cpp b/openlr/candidate_points_getter.cpp
index b0bad2cbe5..6c110ae336 100644
--- a/openlr/candidate_points_getter.cpp
+++ b/openlr/candidate_points_getter.cpp
@@ -30,7 +30,7 @@ void CandidatePointsGetter::GetJunctionPointCandidates(m2::PointD const & p,
         scales::GetUpperScale());
   };
 
-  m_index.ForEachInRect(selectCandidates, rect, scales::GetUpperScale());
+  m_dataSource.ForEachInRect(selectCandidates, rect, scales::GetUpperScale());
 
   // TODO: Move this to a separate stage.
   // 1030292476 Does not match. Some problem occur with points.
diff --git a/openlr/candidate_points_getter.hpp b/openlr/candidate_points_getter.hpp
index f8252732a5..618ddea02f 100644
--- a/openlr/candidate_points_getter.hpp
+++ b/openlr/candidate_points_getter.hpp
@@ -17,10 +17,10 @@ class CandidatePointsGetter
 {
 public:
   CandidatePointsGetter(size_t const maxJunctionCandidates, size_t const maxProjectionCandidates,
-                        DataSourceBase const & index, Graph & graph)
+                        DataSourceBase const & dataSource, Graph & graph)
     : m_maxJunctionCandidates(maxJunctionCandidates)
     , m_maxProjectionCandidates(maxProjectionCandidates)
-    , m_index(index)
+    , m_dataSource(dataSource)
     , m_graph(graph)
   {
   }
@@ -38,7 +38,7 @@ private:
   size_t const m_maxJunctionCandidates;
   size_t const m_maxProjectionCandidates;
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   Graph & m_graph;
 };
 }  // namespace openlr
diff --git a/openlr/decoded_path.cpp b/openlr/decoded_path.cpp
index 3e8bce2bea..33642c2567 100644
--- a/openlr/decoded_path.cpp
+++ b/openlr/decoded_path.cpp
@@ -45,11 +45,11 @@ void LatLonFromXML(pugi::xml_node const & node, ms::LatLon & latLon)
   latLon.lon = node.child("lon").text().as_double();
 }
 
-void FeatureIdFromXML(pugi::xml_node const & node, DataSourceBase const & index, FeatureID & fid)
+void FeatureIdFromXML(pugi::xml_node const & node, DataSourceBase const & dataSource, FeatureID & fid)
 {
   THROW_IF_NODE_IS_EMPTY(node, openlr::DecodedPathLoadError, ("Can't parse CountryName"));
   auto const countryName = node.child("CountryName").text().as_string();
-  fid.m_mwmId = index.GetMwmIdByCountryFile(platform::CountryFile(countryName));
+  fid.m_mwmId = dataSource.GetMwmIdByCountryFile(platform::CountryFile(countryName));
   CHECK(fid.m_mwmId.IsAlive(), ("Can't get mwm id for country", countryName));
   fid.m_index = node.child("Index").text().as_uint();
 }
@@ -109,7 +109,7 @@ void WriteAsMappingForSpark(std::ostream & ost, std::vector<DecodedPath> const &
   }
 }
 
-void PathFromXML(pugi::xml_node const & node, DataSourceBase const & index, Path & p)
+void PathFromXML(pugi::xml_node const & node, DataSourceBase const & dataSource, Path & p)
 {
   auto const edges = node.select_nodes("RoadEdge");
   for (auto const xmlE : edges)
@@ -117,7 +117,7 @@ void PathFromXML(pugi::xml_node const & node, DataSourceBase const & index, Path
     auto e = xmlE.node();
 
     FeatureID fid;
-    FeatureIdFromXML(e.child("FeatureID"), index, fid);
+    FeatureIdFromXML(e.child("FeatureID"), dataSource, fid);
 
     auto const isForward = IsForwardFromXML(e.child("IsForward"));
     auto const segmentId = SegmentIdFromXML(e.child("SegmentId"));
diff --git a/openlr/decoded_path.hpp b/openlr/decoded_path.hpp
index a6a9395108..18875937f3 100644
--- a/openlr/decoded_path.hpp
+++ b/openlr/decoded_path.hpp
@@ -33,7 +33,7 @@ struct DecodedPath
 void WriteAsMappingForSpark(std::string const & fileName, std::vector<DecodedPath> const & paths);
 void WriteAsMappingForSpark(std::ostream & ost, std::vector<DecodedPath> const & paths);
 
-void PathFromXML(pugi::xml_node const & node, DataSourceBase const & index, Path & path);
+void PathFromXML(pugi::xml_node const & node, DataSourceBase const & dataSource, Path & path);
 void PathToXML(Path const & path, pugi::xml_node & node);
 }  // namespace openlr
 
diff --git a/openlr/graph.cpp b/openlr/graph.cpp
index 1e831166ef..c2da01d639 100644
--- a/openlr/graph.cpp
+++ b/openlr/graph.cpp
@@ -30,8 +30,8 @@ void GetRegularEdges(Junction const & junction, IRoadGraph const & graph,
 }
 }  // namespace
 
-Graph::Graph(DataSourceBase const & index, shared_ptr<CarModelFactory> carModelFactory)
-  : m_graph(index, IRoadGraph::Mode::ObeyOnewayTag, carModelFactory)
+Graph::Graph(DataSourceBase const & dataSource, shared_ptr<CarModelFactory> carModelFactory)
+  : m_graph(dataSource, IRoadGraph::Mode::ObeyOnewayTag, carModelFactory)
 {
 }
 
diff --git a/openlr/graph.hpp b/openlr/graph.hpp
index 9db2d5d50c..7a5863a4d2 100644
--- a/openlr/graph.hpp
+++ b/openlr/graph.hpp
@@ -24,7 +24,7 @@ public:
   using EdgeVector = routing::FeaturesRoadGraph::TEdgeVector;
   using Junction = routing::Junction;
 
-  Graph(DataSourceBase const & index, std::shared_ptr<routing::CarModelFactory> carModelFactory);
+  Graph(DataSourceBase const & dataSource, std::shared_ptr<routing::CarModelFactory> carModelFactory);
 
   // Appends edges such as that edge.GetStartJunction() == junction to the |edges|.
   void GetOutgoingEdges(routing::Junction const & junction, EdgeVector & edges);
diff --git a/openlr/openlr_decoder.cpp b/openlr/openlr_decoder.cpp
index fb211aa596..42adfb9689 100644
--- a/openlr/openlr_decoder.cpp
+++ b/openlr/openlr_decoder.cpp
@@ -79,9 +79,9 @@ struct alignas(kCacheLineSize) Stats
   uint32_t m_routesHandled = 0;
 };
 
-bool IsRealVertex(m2::PointD const & p, FeatureID const & fid, DataSource const & index)
+bool IsRealVertex(m2::PointD const & p, FeatureID const & fid, DataSource const & dataSource)
 {
-  DataSource::FeaturesLoaderGuard g(index, fid.m_mwmId);
+  DataSource::FeaturesLoaderGuard g(dataSource, fid.m_mwmId);
   auto const ft = g.GetOriginalFeatureByIndex(fid.m_index);
   bool matched = false;
   ft->ForEachPoint(
@@ -93,20 +93,20 @@ bool IsRealVertex(m2::PointD const & p, FeatureID const & fid, DataSource const
   return matched;
 };
 
-void ExpandFake(Graph::EdgeVector & path, Graph::EdgeVector::iterator edgeIt, DataSource const & index,
+void ExpandFake(Graph::EdgeVector & path, Graph::EdgeVector::iterator edgeIt, DataSource const & dataSource,
                 Graph & g)
 {
   if (!edgeIt->IsFake())
     return;
 
   Graph::EdgeVector edges;
-  if (IsRealVertex(edgeIt->GetStartPoint(), edgeIt->GetFeatureId(), index))
+  if (IsRealVertex(edgeIt->GetStartPoint(), edgeIt->GetFeatureId(), dataSource))
   {
     g.GetRegularOutgoingEdges(edgeIt->GetStartJunction(), edges);
   }
   else
   {
-    ASSERT(IsRealVertex(edgeIt->GetEndPoint(), edgeIt->GetFeatureId(), index), ());
+    ASSERT(IsRealVertex(edgeIt->GetEndPoint(), edgeIt->GetFeatureId(), dataSource), ());
     g.GetRegularIngoingEdges(edgeIt->GetEndJunction(), edges);
   }
 
@@ -128,14 +128,14 @@ void ExpandFake(Graph::EdgeVector & path, Graph::EdgeVector::iterator edgeIt, Da
     path.erase(edgeIt);
 };
 
-void ExpandFakes(DataSource const & index, Graph & g, Graph::EdgeVector & path)
+void ExpandFakes(DataSource const & dataSource, Graph & g, Graph::EdgeVector & path)
 {
   ASSERT(!path.empty(), ());
 
-  ExpandFake(path, begin(path), index, g);
+  ExpandFake(path, begin(path), dataSource, g);
   if (path.empty())
     return;
-  ExpandFake(path, --end(path), index, g);
+  ExpandFake(path, --end(path), dataSource, g);
 }
 
 // Returns an iterator pointing to the first edge that should not be cut off.
@@ -189,9 +189,9 @@ void CopyWithoutOffsets(InputIterator const start, InputIterator const stop, Out
 class SegmentsDecoderV1
 {
 public:
-  SegmentsDecoderV1(DataSourceBase const & index, unique_ptr<CarModelFactory> cmf)
-    : m_roadGraph(index, IRoadGraph::Mode::ObeyOnewayTag, move(cmf))
-    , m_infoGetter(index)
+  SegmentsDecoderV1(DataSourceBase const & dataSource, unique_ptr<CarModelFactory> cmf)
+    : m_roadGraph(dataSource, IRoadGraph::Mode::ObeyOnewayTag, move(cmf))
+    , m_infoGetter(dataSource)
     , m_router(m_roadGraph, m_infoGetter)
   {
   }
@@ -258,8 +258,8 @@ private:
 class SegmentsDecoderV2
 {
 public:
-  SegmentsDecoderV2(DataSource const & index, unique_ptr<CarModelFactory> cmf)
-    : m_index(index), m_graph(index, move(cmf)), m_infoGetter(index)
+  SegmentsDecoderV2(DataSource const & dataSource, unique_ptr<CarModelFactory> cmf)
+    : m_dataSource(dataSource), m_graph(dataSource, move(cmf)), m_infoGetter(dataSource)
   {
   }
 
@@ -279,7 +279,7 @@ public:
     lineCandidates.reserve(points.size());
     LOG(LDEBUG, ("Decoding segment:", segment.m_segmentId, "with", points.size(), "points"));
 
-    CandidatePointsGetter pointsGetter(kMaxJunctionCandidates, kMaxProjectionCandidates, m_index,
+    CandidatePointsGetter pointsGetter(kMaxJunctionCandidates, kMaxProjectionCandidates, m_dataSource,
                                        m_graph);
     CandidatePathsGetter pathsGetter(pointsGetter, m_graph, m_infoGetter, stat);
 
@@ -320,7 +320,7 @@ public:
       return false;
     }
 
-    ExpandFakes(m_index, m_graph, route);
+    ExpandFakes(m_dataSource, m_graph, route);
     ASSERT(none_of(begin(route), end(route), mem_fn(&Graph::Edge::IsFake)), (segment.m_segmentId));
     CopyWithoutOffsets(begin(route), end(route), back_inserter(path.m_path), positiveOffsetM,
                        negativeOffsetM);
@@ -336,7 +336,7 @@ public:
   }
 
 private:
-  DataSource const & m_index;
+  DataSource const & m_dataSource;
   Graph m_graph;
   RoadInfoGetter m_infoGetter;
 };
@@ -378,9 +378,9 @@ bool OpenLRDecoder::SegmentsFilter::Matches(LinearSegment const & segment) const
 }
 
 // OpenLRDecoder -----------------------------------------------------------------------------
-OpenLRDecoder::OpenLRDecoder(vector<DataSource> const & indexes,
+OpenLRDecoder::OpenLRDecoder(vector<DataSource> const & dataSources,
                              CountryParentNameGetter const & countryParentNameGetter)
-  : m_indexes(indexes), m_countryParentNameGetter(countryParentNameGetter)
+  : m_dataSources(dataSources), m_countryParentNameGetter(countryParentNameGetter)
 {
 }
 
@@ -400,14 +400,14 @@ template <typename Decoder, typename Stats>
 void OpenLRDecoder::Decode(vector<LinearSegment> const & segments,
                            uint32_t const numThreads, vector<DecodedPath> & paths)
 {
-  auto const worker = [&segments, &paths, numThreads, this](size_t threadNum, DataSource const & index,
+  auto const worker = [&segments, &paths, numThreads, this](size_t threadNum, DataSource const & dataSource,
                                                             Stats & stat) {
     size_t constexpr kBatchSize = GetOptimalBatchSize();
     size_t constexpr kProgressFrequency = 100;
 
     size_t const numSegments = segments.size();
 
-    Decoder decoder(index, make_unique<CarModelFactory>(m_countryParentNameGetter));
+    Decoder decoder(dataSource, make_unique<CarModelFactory>(m_countryParentNameGetter));
     my::Timer timer;
     for (size_t i = threadNum * kBatchSize; i < numSegments; i += numThreads * kBatchSize)
     {
@@ -430,9 +430,9 @@ void OpenLRDecoder::Decode(vector<LinearSegment> const & segments,
   vector<Stats> stats(numThreads);
   vector<thread> workers;
   for (size_t i = 1; i < numThreads; ++i)
-    workers.emplace_back(worker, i, ref(m_indexes[i]), ref(stats[i]));
+    workers.emplace_back(worker, i, ref(m_dataSources[i]), ref(stats[i]));
 
-  worker(0 /* threadNum */, m_indexes[0], stats[0]);
+  worker(0 /* threadNum */, m_dataSources[0], stats[0]);
   for (auto & worker : workers)
     worker.join();
 
diff --git a/openlr/openlr_decoder.hpp b/openlr/openlr_decoder.hpp
index 0fef1ec57b..f893217718 100644
--- a/openlr/openlr_decoder.hpp
+++ b/openlr/openlr_decoder.hpp
@@ -40,7 +40,7 @@ public:
     bool const m_multipointsOnly;
   };
 
-  OpenLRDecoder(std::vector<DataSource> const & indexes,
+  OpenLRDecoder(std::vector<DataSource> const & dataSources,
                 CountryParentNameGetter const & countryParentNameGetter);
 
   // Maps partner segments to mwm paths. |segments| should be sorted by partner id.
@@ -55,7 +55,7 @@ private:
   void Decode(std::vector<LinearSegment> const & segments, uint32_t const numThreads,
               std::vector<DecodedPath> & paths);
 
-  std::vector<DataSource> const & m_indexes;
+  std::vector<DataSource> const & m_dataSources;
   CountryParentNameGetter m_countryParentNameGetter;
 };
 }  // namespace openlr
diff --git a/openlr/openlr_match_quality/openlr_assessment_tool/mainwindow.cpp b/openlr/openlr_match_quality/openlr_assessment_tool/mainwindow.cpp
index cc8800a49d..8cb93fc125 100644
--- a/openlr/openlr_match_quality/openlr_assessment_tool/mainwindow.cpp
+++ b/openlr/openlr_match_quality/openlr_assessment_tool/mainwindow.cpp
@@ -124,8 +124,8 @@ class PointsControllerDelegate : public PointsControllerDelegateBase
 public:
   PointsControllerDelegate(Framework & framework)
     : m_framework(framework)
-    , m_index(framework.GetIndex())
-    , m_roadGraph(m_index, routing::IRoadGraph::Mode::ObeyOnewayTag,
+    , m_dataSource(framework.GetDataSource())
+    , m_roadGraph(m_dataSource, routing::IRoadGraph::Mode::ObeyOnewayTag,
                   make_unique<routing::CarModelFactory>(storage::CountryParentGetter{}))
   {
   }
@@ -157,7 +157,7 @@ public:
       ft.ForEachPoint(pushPoint, scales::GetUpperScale());
     };
 
-    m_index.ForEachInRect(pushFeaturePoints, rect, scales::GetUpperScale());
+    m_dataSource.ForEachInRect(pushFeaturePoints, rect, scales::GetUpperScale());
     return points;
   }
 
@@ -168,7 +168,7 @@ public:
 
     std::vector<FeaturePoint> points;
     m2::PointD pointOnFt;
-    indexer::ForEachFeatureAtPoint(m_index, [&points, &p, &pointOnFt](FeatureType & ft) {
+    indexer::ForEachFeatureAtPoint(m_dataSource, [&points, &p, &pointOnFt](FeatureType & ft) {
         if (ft.GetFeatureType() != feature::GEOM_LINE)
           return;
 
@@ -229,7 +229,7 @@ public:
 
 private:
   Framework & m_framework;
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   routing::FeaturesRoadGraph m_roadGraph;
 };
 }  // namespace
@@ -309,7 +309,7 @@ MainWindow::MainWindow(Framework & framework)
 void MainWindow::CreateTrafficPanel(string const & dataFilePath)
 {
   m_trafficMode = new TrafficMode(dataFilePath,
-                                  m_framework.GetIndex(),
+                                  m_framework.GetDataSource(),
                                   make_unique<TrafficDrawerDelegate>(m_framework),
                                   make_unique<PointsControllerDelegate>(m_framework));
 
diff --git a/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.cpp b/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.cpp
index 966c22a8e0..141507a8fd 100644
--- a/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.cpp
+++ b/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.cpp
@@ -103,12 +103,12 @@ namespace openlr
 {
 // TrafficMode -------------------------------------------------------------------------------------
 TrafficMode::TrafficMode(std::string const & dataFileName,
-                         DataSourceBase const & index,
+                         DataSourceBase const & dataSource,
                          std::unique_ptr<TrafficDrawerDelegateBase> drawerDelegate,
                          std::unique_ptr<PointsControllerDelegateBase> pointsDelegate,
                          QObject * parent)
   : QAbstractTableModel(parent)
-  , m_index(index)
+  , m_dataSource(dataSource)
   , m_drawerDelegate(move(drawerDelegate))
   , m_pointsDelegate(move(pointsDelegate))
 {
@@ -146,11 +146,11 @@ TrafficMode::TrafficMode(std::string const & dataFileName,
         MYTHROW(TrafficModeError, ("An error occured while parsing: can't parse segment"));
 
       if (auto const route = xmlSegment.child("Route"))
-        openlr::PathFromXML(route, m_index, matchedPath);
+        openlr::PathFromXML(route, m_dataSource, matchedPath);
       if (auto const route = xmlSegment.child("FakeRoute"))
-        openlr::PathFromXML(route, m_index, fakePath);
+        openlr::PathFromXML(route, m_dataSource, fakePath);
       if (auto const route = xmlSegment.child("GoldenRoute"))
-        openlr::PathFromXML(route, m_index, goldenPath);
+        openlr::PathFromXML(route, m_dataSource, goldenPath);
 
       m_segments.emplace_back(segment, matchedPath, fakePath, goldenPath, partnerSegmentXML);
       if (auto const status = xmlSegment.child("Ignored"))
diff --git a/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.hpp b/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.hpp
index 1b1684df1b..42ad40cd24 100644
--- a/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.hpp
+++ b/openlr/openlr_match_quality/openlr_assessment_tool/traffic_mode.hpp
@@ -22,7 +22,6 @@
 #include <QAbstractTableModel>
 #include <Qt>
 
-class Index;
 class QItemSelection;
 class Selection;
 
@@ -69,7 +68,7 @@ class TrafficMode : public QAbstractTableModel
 public:
   // TODO(mgsergio): Check we are on the right mwm. I.e. right mwm version and everything.
   TrafficMode(std::string const & dataFileName,
-              DataSourceBase const & index,
+              DataSourceBase const & dataSource,
               std::unique_ptr<TrafficDrawerDelegateBase> drawerDelegate,
               std::unique_ptr<PointsControllerDelegateBase> pointsDelegate,
               QObject * parent = Q_NULLPTR);
@@ -115,7 +114,7 @@ private:
   void HandlePoint(m2::PointD clickPoint, Qt::MouseButton const button);
   bool StartBuildingPathChecks() const;
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   std::vector<SegmentCorrespondence> m_segments;
   // Non-owning pointer to an element of m_segments.
   SegmentCorrespondence * m_currentSegment = nullptr;
diff --git a/openlr/openlr_stat/openlr_stat.cpp b/openlr/openlr_stat/openlr_stat.cpp
index 351662cfa9..705d1d17d0 100644
--- a/openlr/openlr_stat/openlr_stat.cpp
+++ b/openlr/openlr_stat/openlr_stat.cpp
@@ -58,7 +58,7 @@ int32_t const kMinNumThreads = 1;
 int32_t const kMaxNumThreads = 128;
 int32_t const kHandleAllSegments = -1;
 
-void LoadIndexes(std::string const & pathToMWMFolder, std::vector<DataSource> & indexes)
+void LoadDataSources(std::string const & pathToMWMFolder, std::vector<DataSource> & dataSources)
 {
   CHECK(Platform::IsDirectory(pathToMWMFolder), (pathToMWMFolder, "must be a directory."));
 
@@ -67,8 +67,8 @@ void LoadIndexes(std::string const & pathToMWMFolder, std::vector<DataSource> &
 
   CHECK(!files.empty(), (pathToMWMFolder, "Contains no .mwm files."));
 
-  size_t const numIndexes = indexes.size();
-  std::vector<uint64_t> numCountries(numIndexes);
+  size_t const numDataSources = dataSources.size();
+  std::vector<uint64_t> numCountries(numDataSources);
 
   for (auto const & fileName : files)
   {
@@ -82,9 +82,9 @@ void LoadIndexes(std::string const & pathToMWMFolder, std::vector<DataSource> &
     try
     {
       localFile.SyncWithDisk();
-      for (size_t i = 0; i < numIndexes; ++i)
+      for (size_t i = 0; i < numDataSources; ++i)
       {
-        auto const result = indexes[i].RegisterMap(localFile);
+        auto const result = dataSources[i].RegisterMap(localFile);
         CHECK_EQUAL(result.second, MwmSet::RegResult::Success, ("Can't register mwm:", localFile));
 
         auto const & info = result.first.GetInfo();
@@ -98,7 +98,7 @@ void LoadIndexes(std::string const & pathToMWMFolder, std::vector<DataSource> &
     }
   }
 
-  for (size_t i = 0; i < numIndexes; ++i)
+  for (size_t i = 0; i < numDataSources; ++i)
   {
     if (numCountries[i] == 0)
       LOG(LWARNING, ("No countries for thread", i));
@@ -259,10 +259,10 @@ int main(int argc, char * argv[])
 
   auto const numThreads = static_cast<uint32_t>(FLAGS_num_threads);
 
-  std::vector<DataSource> indexes(numThreads);
-  LoadIndexes(FLAGS_mwms_path, indexes);
+  std::vector<DataSource> dataSources(numThreads);
+  LoadDataSources(FLAGS_mwms_path, dataSources);
 
-  OpenLRDecoder decoder(indexes, storage::CountryParentGetter(FLAGS_countries_filename,
+  OpenLRDecoder decoder(dataSources, storage::CountryParentGetter(FLAGS_countries_filename,
                                                               GetPlatform().ResourcesDir()));
 
   pugi::xml_document document;
diff --git a/openlr/openlr_tests/decoded_path_test.cpp b/openlr/openlr_tests/decoded_path_test.cpp
index 24a73e291b..9f1753bb21 100644
--- a/openlr/openlr_tests/decoded_path_test.cpp
+++ b/openlr/openlr_tests/decoded_path_test.cpp
@@ -65,13 +65,13 @@ void RoughJunctionsInPath(openlr::Path & p)
     e = RoughEdgeJunctions(e);
 }
 
-void TestSerializeDeserialize(openlr::Path const & path, DataSource const & index)
+void TestSerializeDeserialize(openlr::Path const & path, DataSource const & dataSource)
 {
   pugi::xml_document doc;
   openlr::PathToXML(path, doc);
 
   openlr::Path restoredPath;
-  openlr::PathFromXML(doc, index, restoredPath);
+  openlr::PathFromXML(doc, dataSource, restoredPath);
 
   // Fix MercatorBounds::From/ToLatLon floating point error
   // for we could use TEST_EQUAL on result.
@@ -133,25 +133,25 @@ void WithRoad(vector<m2::PointD> const & points, Func && fn)
     builder.Add(TestRoad(points, "Interstate 60", "en"));
   }
 
-  DataSource index;
-  auto const regResult = index.RegisterMap(country);
+  DataSource dataSource;
+  auto const regResult = dataSource.RegisterMap(country);
   TEST_EQUAL(regResult.second, MwmSet::RegResult::Success, ());
 
-  MwmSet::MwmHandle mwmHandle = index.GetMwmHandleById(regResult.first);
+  MwmSet::MwmHandle mwmHandle = dataSource.GetMwmHandleById(regResult.first);
   TEST(mwmHandle.IsAlive(), ());
 
-  DataSource::FeaturesLoaderGuard const guard(index, regResult.first);
+  DataSource::FeaturesLoaderGuard const guard(dataSource, regResult.first);
   FeatureType road;
   TEST(guard.GetFeatureByIndex(0, road), ());
   road.ParseEverything();
 
-  fn(index, road);
+  fn(dataSource, road);
 }
 
 UNIT_TEST(MakePath_Test)
 {
   std::vector<m2::PointD> const points{{0, 0}, {0, 1}, {1, 0}, {1, 1}};
-  WithRoad(points, [&points](DataSource const & index, FeatureType & road) {
+  WithRoad(points, [&points](DataSource const & dataSource, FeatureType & road) {
     auto const & id = road.GetID();
     {
       openlr::Path const expected{
@@ -182,14 +182,14 @@ UNIT_TEST(MakePath_Test)
 
 UNIT_TEST(PathSerializeDeserialize_Test)
 {
-  WithRoad({{0, 0}, {0, 1}, {1, 0}, {1, 1}}, [](DataSource const & index, FeatureType & road) {
+  WithRoad({{0, 0}, {0, 1}, {1, 0}, {1, 1}}, [](DataSource const & dataSource, FeatureType & road) {
     {
       auto const path = MakePath(road, true /* forward */);
-      TestSerializeDeserialize(path, index);
+      TestSerializeDeserialize(path, dataSource);
     }
     {
       auto const path = MakePath(road, false /* forward */);
-      TestSerializeDeserialize(path, index);
+      TestSerializeDeserialize(path, dataSource);
     }
   });
 }
diff --git a/openlr/road_info_getter.cpp b/openlr/road_info_getter.cpp
index 67ee14b06c..96ffac93aa 100644
--- a/openlr/road_info_getter.cpp
+++ b/openlr/road_info_getter.cpp
@@ -10,7 +10,10 @@
 
 namespace openlr
 {
-RoadInfoGetter::RoadInfoGetter(DataSourceBase const & index) : m_index(index), m_c(classif()) {}
+RoadInfoGetter::RoadInfoGetter(DataSourceBase const & dataSource)
+  : m_dataSource(dataSource), m_c(classif())
+{
+}
 
 RoadInfoGetter::RoadInfo RoadInfoGetter::Get(FeatureID const & fid)
 {
@@ -18,7 +21,7 @@ RoadInfoGetter::RoadInfo RoadInfoGetter::Get(FeatureID const & fid)
   if (it != end(m_cache))
     return it->second;
 
-  DataSource::FeaturesLoaderGuard g(m_index, fid.m_mwmId);
+  DataSource::FeaturesLoaderGuard g(m_dataSource, fid.m_mwmId);
   FeatureType ft;
   CHECK(g.GetOriginalFeatureByIndex(fid.m_index, ft), ());
 
diff --git a/openlr/road_info_getter.hpp b/openlr/road_info_getter.hpp
index 4badf247c2..45c7f69060 100644
--- a/openlr/road_info_getter.hpp
+++ b/openlr/road_info_getter.hpp
@@ -28,7 +28,7 @@ public:
     FormOfWay m_fow = FormOfWay::NotAValue;
   };
 
-  RoadInfoGetter(DataSourceBase const & index);
+  RoadInfoGetter(DataSourceBase const & dataSource);
 
   RoadInfo Get(FeatureID const & fid);
 
@@ -36,7 +36,7 @@ public:
   FunctionalRoadClass GetFunctionalRoadClass(feature::TypesHolder const & types) const;
   FormOfWay GetFormOfWay(feature::TypesHolder const & types) const;
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   Classificator const & m_c;
 
   TrunkChecker const m_trunkChecker;
diff --git a/routing/bicycle_directions.cpp b/routing/bicycle_directions.cpp
index ba9ce9c40c..641d1e21ea 100644
--- a/routing/bicycle_directions.cpp
+++ b/routing/bicycle_directions.cpp
@@ -158,8 +158,8 @@ bool BicycleDirectionsEngine::AdjacentEdges::IsAlmostEqual(AdjacentEdges const &
 }
 
 // BicycleDirectionsEngine ------------------------------------------------------------------------
-BicycleDirectionsEngine::BicycleDirectionsEngine(DataSourceBase const & index, shared_ptr<NumMwmIds> numMwmIds)
-  : m_index(index), m_numMwmIds(numMwmIds)
+BicycleDirectionsEngine::BicycleDirectionsEngine(DataSourceBase const & dataSource, shared_ptr<NumMwmIds> numMwmIds)
+  : m_dataSource(dataSource), m_numMwmIds(numMwmIds)
 {
   CHECK(m_numMwmIds, ());
 }
@@ -213,7 +213,7 @@ bool BicycleDirectionsEngine::Generate(IndexRoadGraph const & graph, vector<Junc
 EditableDataSource::FeaturesLoaderGuard & BicycleDirectionsEngine::GetLoader(MwmSet::MwmId const & id)
 {
   if (!m_loader || id != m_loader->GetId())
-    m_loader = make_unique<EditableDataSource::FeaturesLoaderGuard>(m_index, id);
+    m_loader = make_unique<EditableDataSource::FeaturesLoaderGuard>(m_dataSource, id);
   return *m_loader;
 }
 
diff --git a/routing/bicycle_directions.hpp b/routing/bicycle_directions.hpp
index 5fcb6df005..a95d79898e 100644
--- a/routing/bicycle_directions.hpp
+++ b/routing/bicycle_directions.hpp
@@ -28,7 +28,7 @@ public:
 
   using AdjacentEdgesMap = std::map<SegmentRange, AdjacentEdges>;
 
-  BicycleDirectionsEngine(DataSourceBase const & index, std::shared_ptr<NumMwmIds> numMwmIds);
+  BicycleDirectionsEngine(DataSourceBase const & dataSource, std::shared_ptr<NumMwmIds> numMwmIds);
 
   // IDirectionsEngine override:
   bool Generate(IndexRoadGraph const & graph, vector<Junction> const & path,
@@ -56,7 +56,7 @@ private:
 
   AdjacentEdgesMap m_adjacentEdges;
   TUnpackedPathSegments m_pathSegments;
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   std::shared_ptr<NumMwmIds> m_numMwmIds;
   std::unique_ptr<EditableDataSource::FeaturesLoaderGuard> m_loader;
 };
diff --git a/routing/cross_mwm_graph.cpp b/routing/cross_mwm_graph.cpp
index 70051d025c..7351265c5e 100644
--- a/routing/cross_mwm_graph.cpp
+++ b/routing/cross_mwm_graph.cpp
@@ -50,14 +50,14 @@ CrossMwmGraph::CrossMwmGraph(shared_ptr<NumMwmIds> numMwmIds,
                              shared_ptr<m4::Tree<NumMwmId>> numMwmTree,
                              shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory,
                              VehicleType vehicleType, CourntryRectFn const & countryRectFn,
-                             DataSourceBase & index)
-  : m_index(index)
+                             DataSourceBase & dataSource)
+  : m_dataSource(dataSource)
   , m_numMwmIds(numMwmIds)
   , m_numMwmTree(numMwmTree)
   , m_vehicleModelFactory(vehicleModelFactory)
   , m_countryRectFn(countryRectFn)
-  , m_crossMwmIndexGraph(index, numMwmIds, vehicleType)
-  , m_crossMwmTransitGraph(index, numMwmIds, VehicleType::Transit)
+  , m_crossMwmIndexGraph(dataSource, numMwmIds, vehicleType)
+  , m_crossMwmTransitGraph(dataSource, numMwmIds, VehicleType::Transit)
 {
   CHECK(m_numMwmIds, ());
   CHECK(m_vehicleModelFactory, ());
@@ -200,7 +200,7 @@ void CrossMwmGraph::GetTwins(Segment const & s, bool isOutgoing, vector<Segment>
         FindBestTwins(s.GetMwmId(), isOutgoing, ft, p, minDistSegs, twins);
       };
 
-      m_index.ForEachInRect(
+      m_dataSource.ForEachInRect(
         findBestTwins, MercatorBounds::RectByCenterXYAndSizeInMeters(p, kTransitionEqualityDistM),
         scales::GetUpperScale());
 
@@ -258,7 +258,7 @@ TransitionPoints CrossMwmGraph::GetTransitionPoints(Segment const & s, bool isOu
 CrossMwmGraph::MwmStatus CrossMwmGraph::GetMwmStatus(NumMwmId numMwmId,
                                                      string const & sectionName) const
 {
-  MwmSet::MwmHandle handle = m_index.GetMwmHandleByCountryFile(m_numMwmIds->GetFile(numMwmId));
+  MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleByCountryFile(m_numMwmIds->GetFile(numMwmId));
   if (!handle.IsAlive())
     return MwmStatus::NotLoaded;
 
diff --git a/routing/cross_mwm_graph.hpp b/routing/cross_mwm_graph.hpp
index 4735e13cd9..601ff16ad6 100644
--- a/routing/cross_mwm_graph.hpp
+++ b/routing/cross_mwm_graph.hpp
@@ -37,7 +37,7 @@ public:
 
   CrossMwmGraph(std::shared_ptr<NumMwmIds> numMwmIds, shared_ptr<m4::Tree<NumMwmId>> numMwmTree,
                 std::shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory, VehicleType vehicleType,
-                CourntryRectFn const & countryRectFn, DataSourceBase & index);
+                CourntryRectFn const & countryRectFn, DataSourceBase & dataSource);
 
   /// \brief Transition segment is a segment which is crossed by mwm border. That means
   /// start and finish of such segment have to lie in different mwms. If a segment is
@@ -148,7 +148,7 @@ private:
   void DeserializeTransitions(std::vector<NumMwmId> const & mwmIds);
   void DeserializeTransitTransitions(std::vector<NumMwmId> const & mwmIds);
 
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   std::shared_ptr<NumMwmIds> m_numMwmIds;
   std::shared_ptr<m4::Tree<NumMwmId>> m_numMwmTree;
   std::shared_ptr<VehicleModelFactoryInterface> m_vehicleModelFactory;
diff --git a/routing/cross_mwm_index_graph.hpp b/routing/cross_mwm_index_graph.hpp
index c3faf1d7a6..eb69f9bb1d 100644
--- a/routing/cross_mwm_index_graph.hpp
+++ b/routing/cross_mwm_index_graph.hpp
@@ -66,8 +66,8 @@ class CrossMwmIndexGraph final
 public:
   using ReaderSourceFile = ReaderSource<FilesContainerR::TReader>;
 
-  CrossMwmIndexGraph(DataSourceBase & index, std::shared_ptr<NumMwmIds> numMwmIds, VehicleType vehicleType)
-    : m_index(index), m_numMwmIds(numMwmIds), m_vehicleType(vehicleType)
+  CrossMwmIndexGraph(DataSourceBase & dataSource, std::shared_ptr<NumMwmIds> numMwmIds, VehicleType vehicleType)
+    : m_dataSource(dataSource), m_numMwmIds(numMwmIds), m_vehicleType(vehicleType)
   {
   }
 
@@ -172,7 +172,7 @@ private:
   template <typename Fn>
   CrossMwmConnector<CrossMwmId> const & Deserialize(NumMwmId numMwmId, Fn && fn)
   {
-    MwmSet::MwmHandle handle = m_index.GetMwmHandleByCountryFile(m_numMwmIds->GetFile(numMwmId));
+    MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleByCountryFile(m_numMwmIds->GetFile(numMwmId));
     if (!handle.IsAlive())
       MYTHROW(RoutingException, ("Mwm", m_numMwmIds->GetFile(numMwmId), "cannot be loaded."));
 
@@ -193,7 +193,7 @@ private:
     return it->second;
   }
 
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   std::shared_ptr<NumMwmIds> m_numMwmIds;
   VehicleType m_vehicleType;
 
diff --git a/routing/features_road_graph.cpp b/routing/features_road_graph.cpp
index 34b1040a3a..459b88d843 100644
--- a/routing/features_road_graph.cpp
+++ b/routing/features_road_graph.cpp
@@ -30,13 +30,13 @@ double constexpr kMwmCrossingNodeEqualityRadiusMeters = 100.0;
 
 double GetRoadCrossingRadiusMeters() { return kMwmRoadCrossingRadiusMeters; }
 
-FeaturesRoadGraph::Value::Value(DataSourceBase const & index, MwmSet::MwmHandle handle)
+FeaturesRoadGraph::Value::Value(DataSourceBase const & dataSource, MwmSet::MwmHandle handle)
   : m_mwmHandle(move(handle))
 {
   if (!m_mwmHandle.IsAlive())
     return;
 
-  m_altitudeLoader = make_unique<feature::AltitudeLoader>(index, m_mwmHandle.GetId());
+  m_altitudeLoader = make_unique<feature::AltitudeLoader>(dataSource, m_mwmHandle.GetId());
 }
 
 FeaturesRoadGraph::CrossCountryVehicleModel::CrossCountryVehicleModel(
@@ -111,9 +111,9 @@ void FeaturesRoadGraph::RoadInfoCache::Clear()
 {
   m_cache.clear();
 }
-FeaturesRoadGraph::FeaturesRoadGraph(DataSourceBase const & index, IRoadGraph::Mode mode,
+FeaturesRoadGraph::FeaturesRoadGraph(DataSourceBase const & dataSource, IRoadGraph::Mode mode,
                                      shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory)
-  : m_index(index), m_mode(mode), m_vehicleModel(vehicleModelFactory)
+  : m_dataSource(dataSource), m_mode(mode), m_vehicleModel(vehicleModelFactory)
 {
 }
 
@@ -171,7 +171,7 @@ void FeaturesRoadGraph::ForEachFeatureClosestToCross(m2::PointD const & cross,
 {
   CrossFeaturesLoader featuresLoader(*this, edgesLoader);
   m2::RectD const rect = MercatorBounds::RectByCenterXYAndSizeInMeters(cross, kMwmRoadCrossingRadiusMeters);
-  m_index.ForEachInRect(featuresLoader, rect, GetStreetReadScale());
+  m_dataSource.ForEachInRect(featuresLoader, rect, GetStreetReadScale());
 }
 
 void FeaturesRoadGraph::FindClosestEdges(m2::PointD const & point, uint32_t count,
@@ -195,7 +195,7 @@ void FeaturesRoadGraph::FindClosestEdges(m2::PointD const & point, uint32_t coun
     finder.AddInformationSource(featureId, roadInfo);
   };
 
-  m_index.ForEachInRect(
+  m_dataSource.ForEachInRect(
       f, MercatorBounds::RectByCenterXYAndSizeInMeters(point, kMwmCrossingNodeEqualityRadiusMeters),
       GetStreetReadScale());
 
@@ -205,7 +205,7 @@ void FeaturesRoadGraph::FindClosestEdges(m2::PointD const & point, uint32_t coun
 void FeaturesRoadGraph::GetFeatureTypes(FeatureID const & featureId, feature::TypesHolder & types) const
 {
   FeatureType ft;
-  EditableDataSource::FeaturesLoaderGuard loader(m_index, featureId.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard loader(m_dataSource, featureId.m_mwmId);
   if (!loader.GetFeatureByIndex(featureId.m_index, ft))
     return;
 
@@ -236,7 +236,7 @@ void FeaturesRoadGraph::GetJunctionTypes(Junction const & junction, feature::Typ
   };
 
   m2::RectD const rect = MercatorBounds::RectByCenterXYAndSizeInMeters(cross, kMwmRoadCrossingRadiusMeters);
-  m_index.ForEachInRect(f, rect, GetStreetReadScale());
+  m_dataSource.ForEachInRect(f, rect, GetStreetReadScale());
 }
 
 IRoadGraph::Mode FeaturesRoadGraph::GetMode() const
@@ -306,7 +306,7 @@ IRoadGraph::RoadInfo const & FeaturesRoadGraph::GetCachedRoadInfo(FeatureID cons
 
   FeatureType ft;
 
-  EditableDataSource::FeaturesLoaderGuard loader(m_index, featureId.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard loader(m_dataSource, featureId.m_mwmId);
 
   if (!loader.GetFeatureByIndex(featureId.m_index, ft))
     return ri;
@@ -341,7 +341,7 @@ FeaturesRoadGraph::Value const & FeaturesRoadGraph::LockMwm(MwmSet::MwmId const
   if (itr != m_mwmLocks.end())
     return itr->second;
 
-  return m_mwmLocks.insert(make_pair(move(mwmId), Value(m_index, m_index.GetMwmHandleById(mwmId))))
+  return m_mwmLocks.insert(make_pair(move(mwmId), Value(m_dataSource, m_dataSource.GetMwmHandleById(mwmId))))
       .first->second;
 }
 }  // namespace routing
diff --git a/routing/features_road_graph.hpp b/routing/features_road_graph.hpp
index c2e559d481..59bcc98567 100644
--- a/routing/features_road_graph.hpp
+++ b/routing/features_road_graph.hpp
@@ -63,7 +63,7 @@ private:
   };
 
 public:
-  FeaturesRoadGraph(DataSourceBase const & index, IRoadGraph::Mode mode,
+  FeaturesRoadGraph(DataSourceBase const & dataSource, IRoadGraph::Mode mode,
                     shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory);
 
   static int GetStreetReadScale();
@@ -89,7 +89,7 @@ private:
   struct Value
   {
     Value() = default;
-    Value(DataSourceBase const & index, MwmSet::MwmHandle handle);
+    Value(DataSourceBase const & dataSource, MwmSet::MwmHandle handle);
 
     bool IsAlive() const { return m_mwmHandle.IsAlive(); }
 
@@ -112,7 +112,7 @@ private:
 
   Value const & LockMwm(MwmSet::MwmId const & mwmId) const;
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   IRoadGraph::Mode const m_mode;
   mutable RoadInfoCache m_cache;
   mutable CrossCountryVehicleModel m_vehicleModel;
diff --git a/routing/geometry.cpp b/routing/geometry.cpp
index 03709186f3..6b78be91b1 100644
--- a/routing/geometry.cpp
+++ b/routing/geometry.cpp
@@ -25,7 +25,7 @@ size_t constexpr kRoadsCacheSize = 5000;
 class GeometryLoaderImpl final : public GeometryLoader
 {
 public:
-  GeometryLoaderImpl(DataSourceBase const & index, MwmSet::MwmHandle const & handle,
+  GeometryLoaderImpl(DataSourceBase const & dataSource, MwmSet::MwmHandle const & handle,
                      shared_ptr<VehicleModelInterface> vehicleModel, bool loadAltitudes);
 
   // GeometryLoader overrides:
@@ -39,12 +39,12 @@ private:
   bool const m_loadAltitudes;
 };
 
-GeometryLoaderImpl::GeometryLoaderImpl(DataSourceBase const & index, MwmSet::MwmHandle const & handle,
+GeometryLoaderImpl::GeometryLoaderImpl(DataSourceBase const & dataSource, MwmSet::MwmHandle const & handle,
                                        shared_ptr<VehicleModelInterface> vehicleModel, bool loadAltitudes)
   : m_vehicleModel(move(vehicleModel))
-  , m_guard(index, handle.GetId())
+  , m_guard(dataSource, handle.GetId())
   , m_country(handle.GetInfo()->GetCountryName())
-  , m_altitudeLoader(index, handle.GetId())
+  , m_altitudeLoader(dataSource, handle.GetId())
   , m_loadAltitudes(loadAltitudes)
 {
   CHECK(handle.IsAlive(), ());
@@ -161,13 +161,13 @@ RoadGeometry const & Geometry::GetRoad(uint32_t featureId)
 }
 
 // static
-unique_ptr<GeometryLoader> GeometryLoader::Create(DataSourceBase const & index,
+unique_ptr<GeometryLoader> GeometryLoader::Create(DataSourceBase const & dataSource,
                                                   MwmSet::MwmHandle const & handle,
                                                   shared_ptr<VehicleModelInterface> vehicleModel,
                                                   bool loadAltitudes)
 {
   CHECK(handle.IsAlive(), ());
-  return make_unique<GeometryLoaderImpl>(index, handle, vehicleModel, loadAltitudes);
+  return make_unique<GeometryLoaderImpl>(dataSource, handle, vehicleModel, loadAltitudes);
 }
 
 // static
diff --git a/routing/geometry.hpp b/routing/geometry.hpp
index cdbb9d157e..5ea0b2cfa8 100644
--- a/routing/geometry.hpp
+++ b/routing/geometry.hpp
@@ -79,7 +79,7 @@ public:
   virtual void Load(uint32_t featureId, RoadGeometry & road) = 0;
 
   // handle should be alive: it is caller responsibility to check it.
-  static std::unique_ptr<GeometryLoader> Create(DataSourceBase const & index,
+  static std::unique_ptr<GeometryLoader> Create(DataSourceBase const & dataSource,
                                                 MwmSet::MwmHandle const & handle,
                                                 std::shared_ptr<VehicleModelInterface> vehicleModel,
                                                 bool loadAltitudes);
diff --git a/routing/index_graph_loader.cpp b/routing/index_graph_loader.cpp
index b1218e1aba..e0221fd623 100644
--- a/routing/index_graph_loader.cpp
+++ b/routing/index_graph_loader.cpp
@@ -22,7 +22,7 @@ class IndexGraphLoaderImpl final : public IndexGraphLoader
 public:
   IndexGraphLoaderImpl(VehicleType vehicleType, bool loadAltitudes, shared_ptr<NumMwmIds> numMwmIds,
                        shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory,
-                       shared_ptr<EdgeEstimator> estimator, DataSourceBase & index);
+                       shared_ptr<EdgeEstimator> estimator, DataSourceBase & dataSource);
 
   // IndexGraphLoader overrides:
   Geometry & GetGeometry(NumMwmId numMwmId) override;
@@ -41,7 +41,7 @@ private:
 
   VehicleType m_vehicleType;
   bool m_loadAltitudes;
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   shared_ptr<NumMwmIds> m_numMwmIds;
   shared_ptr<VehicleModelFactoryInterface> m_vehicleModelFactory;
   shared_ptr<EdgeEstimator> m_estimator;
@@ -51,10 +51,10 @@ private:
 IndexGraphLoaderImpl::IndexGraphLoaderImpl(
     VehicleType vehicleType, bool loadAltitudes, shared_ptr<NumMwmIds> numMwmIds,
     shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory,
-    shared_ptr<EdgeEstimator> estimator, DataSourceBase & index)
+    shared_ptr<EdgeEstimator> estimator, DataSourceBase & dataSource)
   : m_vehicleType(vehicleType)
   , m_loadAltitudes(loadAltitudes)
-  , m_index(index)
+  , m_dataSource(dataSource)
   , m_numMwmIds(numMwmIds)
   , m_vehicleModelFactory(vehicleModelFactory)
   , m_estimator(estimator)
@@ -88,7 +88,7 @@ IndexGraph & IndexGraphLoaderImpl::GetIndexGraph(NumMwmId numMwmId)
 IndexGraphLoaderImpl::GeometryIndexGraph & IndexGraphLoaderImpl::CreateGeometry(NumMwmId numMwmId)
 {
   platform::CountryFile const & file = m_numMwmIds->GetFile(numMwmId);
-  MwmSet::MwmHandle handle = m_index.GetMwmHandleByCountryFile(file);
+  MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleByCountryFile(file);
   if (!handle.IsAlive())
     MYTHROW(RoutingException, ("Can't get mwm handle for", file));
 
@@ -97,7 +97,7 @@ IndexGraphLoaderImpl::GeometryIndexGraph & IndexGraphLoaderImpl::CreateGeometry(
 
   auto & graph = m_graphs[numMwmId];
   graph.m_geometry =
-      make_shared<Geometry>(GeometryLoader::Create(m_index, handle, vehicleModel, m_loadAltitudes));
+      make_shared<Geometry>(GeometryLoader::Create(m_dataSource, handle, vehicleModel, m_loadAltitudes));
   return graph;
 }
 
@@ -106,7 +106,7 @@ IndexGraphLoaderImpl::GeometryIndexGraph & IndexGraphLoaderImpl::CreateIndexGrap
 {
   CHECK(graph.m_geometry, ());
   platform::CountryFile const & file = m_numMwmIds->GetFile(numMwmId);
-  MwmSet::MwmHandle handle = m_index.GetMwmHandleByCountryFile(file);
+  MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleByCountryFile(file);
   if (!handle.IsAlive())
     MYTHROW(RoutingException, ("Can't get mwm handle for", file));
 
@@ -149,10 +149,10 @@ namespace routing
 unique_ptr<IndexGraphLoader> IndexGraphLoader::Create(
     VehicleType vehicleType, bool loadAltitudes, shared_ptr<NumMwmIds> numMwmIds,
     shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory, shared_ptr<EdgeEstimator> estimator,
-    DataSourceBase & index)
+    DataSourceBase & dataSource)
 {
   return make_unique<IndexGraphLoaderImpl>(vehicleType, loadAltitudes, numMwmIds, vehicleModelFactory,
-                                           estimator, index);
+                                           estimator, dataSource);
 }
 
 void DeserializeIndexGraph(MwmValue const & mwmValue, VehicleType vehicleType, IndexGraph & graph)
diff --git a/routing/index_graph_loader.hpp b/routing/index_graph_loader.hpp
index bcb8336d81..e46b64f33a 100644
--- a/routing/index_graph_loader.hpp
+++ b/routing/index_graph_loader.hpp
@@ -26,7 +26,7 @@ public:
   static std::unique_ptr<IndexGraphLoader> Create(
       VehicleType vehicleType, bool loadAltitudes, std::shared_ptr<NumMwmIds> numMwmIds,
       std::shared_ptr<VehicleModelFactoryInterface> vehicleModelFactory,
-      std::shared_ptr<EdgeEstimator> estimator, DataSourceBase & index);
+      std::shared_ptr<EdgeEstimator> estimator, DataSourceBase & dataSource);
 };
 
 void DeserializeIndexGraph(MwmValue const & mwmValue, VehicleType vehicleType, IndexGraph & graph);
diff --git a/routing/index_road_graph.cpp b/routing/index_road_graph.cpp
index e8e81d863c..5d50fd2f38 100644
--- a/routing/index_road_graph.cpp
+++ b/routing/index_road_graph.cpp
@@ -13,8 +13,8 @@ namespace routing
 {
 IndexRoadGraph::IndexRoadGraph(shared_ptr<NumMwmIds> numMwmIds, IndexGraphStarter & starter,
                                vector<Segment> const & segments, vector<Junction> const & junctions,
-                               DataSourceBase & index)
-  : m_index(index), m_numMwmIds(numMwmIds), m_starter(starter), m_segments(segments)
+                               DataSourceBase & dataSource)
+  : m_dataSource(dataSource), m_numMwmIds(numMwmIds), m_starter(starter), m_segments(segments)
 {
   //    j0     j1     j2     j3
   //    *--s0--*--s1--*--s2--*
@@ -60,7 +60,7 @@ void IndexRoadGraph::GetEdgeTypes(Edge const & edge, feature::TypesHolder & type
 
   FeatureID const featureId = edge.GetFeatureId();
   FeatureType ft;
-  EditableDataSource::FeaturesLoaderGuard loader(m_index, featureId.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard loader(m_dataSource, featureId.m_mwmId);
   if (!loader.GetFeatureByIndex(featureId.m_index, ft))
   {
     LOG(LERROR, ("Can't load types for feature", featureId));
@@ -92,7 +92,7 @@ void IndexRoadGraph::GetRouteEdges(TEdgeVector & edges) const
       if (m_starter.ConvertToReal(real))
       {
         platform::CountryFile const & file = m_numMwmIds->GetFile(real.GetMwmId());
-        MwmSet::MwmId const mwmId = m_index.GetMwmIdByCountryFile(file);
+        MwmSet::MwmId const mwmId = m_dataSource.GetMwmIdByCountryFile(file);
         edges.push_back(Edge::MakeFakeWithRealPart(FeatureID(mwmId, real.GetFeatureId()),
                                                    real.IsForward(), real.GetSegmentIdx(),
                                                    junctionFrom, junctionTo));
@@ -105,7 +105,7 @@ void IndexRoadGraph::GetRouteEdges(TEdgeVector & edges) const
     else
     {
       platform::CountryFile const & file = m_numMwmIds->GetFile(segment.GetMwmId());
-      MwmSet::MwmId const mwmId = m_index.GetMwmIdByCountryFile(file);
+      MwmSet::MwmId const mwmId = m_dataSource.GetMwmIdByCountryFile(file);
       edges.push_back(Edge::MakeReal(FeatureID(mwmId, segment.GetFeatureId()), segment.IsForward(),
                                      segment.GetSegmentIdx(), junctionFrom, junctionTo));
     }
@@ -137,7 +137,7 @@ void IndexRoadGraph::GetEdges(Junction const & junction, bool isOutgoing, TEdgeV
       continue;
 
     platform::CountryFile const & file = m_numMwmIds->GetFile(segment.GetMwmId());
-    MwmSet::MwmId const mwmId = m_index.GetMwmIdByCountryFile(file);
+    MwmSet::MwmId const mwmId = m_dataSource.GetMwmIdByCountryFile(file);
 
     edges.push_back(Edge::MakeReal(FeatureID(mwmId, segment.GetFeatureId()), segment.IsForward(),
                                    segment.GetSegmentIdx(),
diff --git a/routing/index_road_graph.hpp b/routing/index_road_graph.hpp
index 804b2ac68a..43e8f6d881 100644
--- a/routing/index_road_graph.hpp
+++ b/routing/index_road_graph.hpp
@@ -19,7 +19,7 @@ class IndexRoadGraph : public RoadGraphBase
 public:
   IndexRoadGraph(std::shared_ptr<NumMwmIds> numMwmIds, IndexGraphStarter & starter,
                  std::vector<Segment> const & segments, std::vector<Junction> const & junctions,
-                 DataSourceBase & index);
+                 DataSourceBase & dataSource);
 
   // IRoadGraphBase overrides:
   virtual void GetOutgoingEdges(Junction const & junction, TEdgeVector & edges) const override;
@@ -35,7 +35,7 @@ private:
   void GetEdges(Junction const & junction, bool isOutgoing, TEdgeVector & edges) const;
   std::vector<Segment> const & GetSegments(Junction const & junction, bool isOutgoing) const;
 
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   std::shared_ptr<NumMwmIds> m_numMwmIds;
   IndexGraphStarter & m_starter;
   std::vector<Segment> m_segments;
diff --git a/routing/index_router.cpp b/routing/index_router.cpp
index 1f0aa06d65..472767b771 100644
--- a/routing/index_router.cpp
+++ b/routing/index_router.cpp
@@ -101,7 +101,7 @@ shared_ptr<VehicleModelFactoryInterface> CreateVehicleModelFactory(
 }
 
 unique_ptr<IDirectionsEngine> CreateDirectionsEngine(VehicleType vehicleType,
-                                                     shared_ptr<NumMwmIds> numMwmIds, DataSourceBase & index)
+                                                     shared_ptr<NumMwmIds> numMwmIds, DataSourceBase & dataSource)
 {
   switch (vehicleType)
   {
@@ -110,7 +110,7 @@ unique_ptr<IDirectionsEngine> CreateDirectionsEngine(VehicleType vehicleType,
   case VehicleType::Bicycle:
   // @TODO Bicycle turn generation engine is used now. It's ok for the time being.
   // But later a special car turn generation engine should be implemented.
-  case VehicleType::Car: return make_unique<BicycleDirectionsEngine>(index, numMwmIds);
+  case VehicleType::Car: return make_unique<BicycleDirectionsEngine>(dataSource, numMwmIds);
   case VehicleType::Count:
     CHECK(false, ("Can't create DirectionsEngine for", vehicleType));
     return nullptr;
@@ -154,11 +154,11 @@ bool MwmHasRoutingData(version::MwmTraits const & traits)
   return traits.HasRoutingIndex() && traits.HasCrossMwmSection();
 }
 
-void GetOutdatedMwms(DataSourceBase & index, vector<string> & outdatedMwms)
+void GetOutdatedMwms(DataSourceBase & dataSource, vector<string> & outdatedMwms)
 {
   outdatedMwms.clear();
   vector<shared_ptr<MwmInfo>> infos;
-  index.GetMwmsInfo(infos);
+  dataSource.GetMwmsInfo(infos);
 
   for (auto const & info : infos)
   {
@@ -274,18 +274,18 @@ IndexRouter::IndexRouter(VehicleType vehicleType, bool loadAltitudes,
                          CountryParentNameGetterFn const & countryParentNameGetterFn,
                          TCountryFileFn const & countryFileFn, CourntryRectFn const & countryRectFn,
                          shared_ptr<NumMwmIds> numMwmIds, unique_ptr<m4::Tree<NumMwmId>> numMwmTree,
-                         traffic::TrafficCache const & trafficCache, DataSourceBase & index)
+                         traffic::TrafficCache const & trafficCache, DataSourceBase & dataSource)
   : m_vehicleType(vehicleType)
   , m_loadAltitudes(loadAltitudes)
   , m_name("astar-bidirectional-" + ToString(m_vehicleType))
-  , m_index(index)
+  , m_dataSource(dataSource)
   , m_vehicleModelFactory(CreateVehicleModelFactory(m_vehicleType, countryParentNameGetterFn))
   , m_countryFileFn(countryFileFn)
   , m_countryRectFn(countryRectFn)
   , m_numMwmIds(move(numMwmIds))
   , m_numMwmTree(move(numMwmTree))
   , m_trafficStash(CreateTrafficStash(m_vehicleType, m_numMwmIds, trafficCache))
-  , m_roadGraph(m_index,
+  , m_roadGraph(m_dataSource,
                 vehicleType == VehicleType::Pedestrian || vehicleType == VehicleType::Transit
                     ? IRoadGraph::Mode::IgnoreOnewayTag
                     : IRoadGraph::Mode::ObeyOnewayTag,
@@ -293,7 +293,7 @@ IndexRouter::IndexRouter(VehicleType vehicleType, bool loadAltitudes,
   , m_estimator(EdgeEstimator::Create(
         m_vehicleType, CalcMaxSpeed(*m_numMwmIds, *m_vehicleModelFactory, m_vehicleType),
         CalcOffroadSpeed(*m_vehicleModelFactory), m_trafficStash))
-  , m_directionsEngine(CreateDirectionsEngine(m_vehicleType, m_numMwmIds, m_index))
+  , m_directionsEngine(CreateDirectionsEngine(m_vehicleType, m_numMwmIds, m_dataSource))
 {
   CHECK(!m_name.empty(), ());
   CHECK(m_numMwmIds, ());
@@ -325,7 +325,7 @@ RouterResultCode IndexRouter::CalculateRoute(Checkpoints const & checkpoints,
                                              RouterDelegate const & delegate, Route & route)
 {
   vector<string> outdatedMwms;
-  GetOutdatedMwms(m_index, outdatedMwms);
+  GetOutdatedMwms(m_dataSource, outdatedMwms);
 
   if (!outdatedMwms.empty())
   {
@@ -385,7 +385,7 @@ RouterResultCode IndexRouter::DoCalculateRoute(Checkpoints const & checkpoints,
     }
 
     auto const country = platform::CountryFile(countryName);
-    if (!m_index.IsLoaded(country))
+    if (!m_dataSource.IsLoaded(country))
       route.AddAbsentCountry(country.GetName());
   }
 
@@ -664,16 +664,16 @@ unique_ptr<WorldGraph> IndexRouter::MakeWorldGraph()
   auto crossMwmGraph = make_unique<CrossMwmGraph>(
       m_numMwmIds, m_numMwmTree, m_vehicleModelFactory,
       m_vehicleType == VehicleType::Transit ? VehicleType::Pedestrian : m_vehicleType,
-      m_countryRectFn, m_index);
+      m_countryRectFn, m_dataSource);
   auto indexGraphLoader = IndexGraphLoader::Create(
       m_vehicleType == VehicleType::Transit ? VehicleType::Pedestrian : m_vehicleType,
-      m_loadAltitudes, m_numMwmIds, m_vehicleModelFactory, m_estimator, m_index);
+      m_loadAltitudes, m_numMwmIds, m_vehicleModelFactory, m_estimator, m_dataSource);
   if (m_vehicleType != VehicleType::Transit)
   {
     return make_unique<SingleVehicleWorldGraph>(move(crossMwmGraph), move(indexGraphLoader),
                                                 m_estimator);
   }
-  auto transitGraphLoader = TransitGraphLoader::Create(m_index, m_numMwmIds, m_estimator);
+  auto transitGraphLoader = TransitGraphLoader::Create(m_dataSource, m_numMwmIds, m_estimator);
   return make_unique<TransitWorldGraph>(move(crossMwmGraph), move(indexGraphLoader),
                                         move(transitGraphLoader), m_estimator);
 }
@@ -683,7 +683,7 @@ bool IndexRouter::FindBestSegment(m2::PointD const & point, m2::PointD const & d
                                   bool & bestSegmentIsAlmostCodirectional) const
 {
   auto const file = platform::CountryFile(m_countryFileFn(point));
-  MwmSet::MwmHandle handle = m_index.GetMwmHandleByCountryFile(file);
+  MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleByCountryFile(file);
   if (!handle.IsAlive())
     MYTHROW(MwmIsNotAliveException, ("Can't get mwm handle for", file));
 
@@ -853,7 +853,7 @@ RouterResultCode IndexRouter::RedressRoute(vector<Segment> const & segments,
   for (size_t i = 0; i < numPoints; ++i)
     junctions.emplace_back(starter.GetRouteJunction(segments, i));
 
-  IndexRoadGraph roadGraph(m_numMwmIds, starter, segments, junctions, m_index);
+  IndexRoadGraph roadGraph(m_numMwmIds, starter, segments, junctions, m_dataSource);
   starter.GetGraph().SetMode(WorldGraph::Mode::NoLeaps);
 
   Route::TTimes times;
@@ -905,7 +905,7 @@ bool IndexRouter::DoesTransitSectionExist(NumMwmId numMwmId) const
   CHECK(m_numMwmIds, ());
   platform::CountryFile const & file = m_numMwmIds->GetFile(numMwmId);
 
-  MwmSet::MwmHandle handle = m_index.GetMwmHandleByCountryFile(file);
+  MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleByCountryFile(file);
   if (!handle.IsAlive())
     MYTHROW(RoutingException, ("Can't get mwm handle for", file));
 
diff --git a/routing/index_router.hpp b/routing/index_router.hpp
index 4b7ec5b7b6..41d7b04013 100644
--- a/routing/index_router.hpp
+++ b/routing/index_router.hpp
@@ -65,7 +65,7 @@ public:
   IndexRouter(VehicleType vehicleType, bool loadAltitudes, CountryParentNameGetterFn const & countryParentNameGetterFn,
               TCountryFileFn const & countryFileFn, CourntryRectFn const & countryRectFn,
               shared_ptr<NumMwmIds> numMwmIds, unique_ptr<m4::Tree<NumMwmId>> numMwmTree,
-              traffic::TrafficCache const & trafficCache, DataSourceBase & index);
+              traffic::TrafficCache const & trafficCache, DataSourceBase & dataSource);
 
   std::unique_ptr<WorldGraph> MakeSingleMwmWorldGraph();
   bool FindBestSegment(m2::PointD const & point, m2::PointD const & direction,
@@ -147,7 +147,7 @@ private:
   VehicleType m_vehicleType;
   bool m_loadAltitudes;
   std::string const m_name;
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   std::shared_ptr<VehicleModelFactoryInterface> m_vehicleModelFactory;
 
   TCountryFileFn const m_countryFileFn;
diff --git a/routing/routing_benchmarks/bicycle_routing_tests.cpp b/routing/routing_benchmarks/bicycle_routing_tests.cpp
index f7d09bac20..5b3e1d66b8 100644
--- a/routing/routing_benchmarks/bicycle_routing_tests.cpp
+++ b/routing/routing_benchmarks/bicycle_routing_tests.cpp
@@ -29,7 +29,7 @@ protected:
     shared_ptr<routing::NumMwmIds> numMwmIds) override
   {
     unique_ptr<routing::IDirectionsEngine> engine(new routing::BicycleDirectionsEngine(
-        m_index, numMwmIds));
+        m_dataSource, numMwmIds));
     return engine;
   }
 
diff --git a/routing/routing_benchmarks/helpers.cpp b/routing/routing_benchmarks/helpers.cpp
index 48b726790d..abddbcd2b3 100644
--- a/routing/routing_benchmarks/helpers.cpp
+++ b/routing/routing_benchmarks/helpers.cpp
@@ -81,11 +81,11 @@ RoutingTest::RoutingTest(routing::IRoadGraph::Mode mode, set<string> const & nee
     if (m_neededMaps.count(name) == 0)
       continue;
 
-    UNUSED_VALUE(m_index.RegisterMap(localFile));
+    UNUSED_VALUE(m_dataSource.RegisterMap(localFile));
 
     auto const & countryFile = localFile.GetCountryFile();
-    TEST(m_index.IsLoaded(countryFile), ());
-    MwmSet::MwmId const id = m_index.GetMwmIdByCountryFile(countryFile);
+    TEST(m_dataSource.IsLoaded(countryFile), ());
+    MwmSet::MwmId const id = m_dataSource.GetMwmIdByCountryFile(countryFile);
     TEST(id.IsAlive(), ());
 
     registeredMaps.insert(name);
@@ -153,13 +153,13 @@ unique_ptr<routing::IRouter> RoutingTest::CreateRouter(string const & name)
   }
 
   unique_ptr<routing::IRouter> router = integration::CreateVehicleRouter(
-      m_index, *m_cig, m_trafficCache, neededLocalFiles, routing::VehicleType::Pedestrian);
+      m_dataSource, *m_cig, m_trafficCache, neededLocalFiles, routing::VehicleType::Pedestrian);
   return router;
 }
 
 void RoutingTest::GetNearestEdges(m2::PointD const & pt,
                                   vector<pair<routing::Edge, routing::Junction>> & edges)
 {
-  routing::FeaturesRoadGraph graph(m_index, m_mode, CreateModelFactory());
+  routing::FeaturesRoadGraph graph(m_dataSource, m_mode, CreateModelFactory());
   graph.FindClosestEdges(pt, 1 /* count */, edges);
 }
diff --git a/routing/routing_benchmarks/helpers.hpp b/routing/routing_benchmarks/helpers.hpp
index 1d6d948140..31f0444a73 100644
--- a/routing/routing_benchmarks/helpers.hpp
+++ b/routing/routing_benchmarks/helpers.hpp
@@ -42,7 +42,7 @@ protected:
                        std::vector<std::pair<routing::Edge, routing::Junction>> & edges);
 
   routing::IRoadGraph::Mode const m_mode;
-  DataSource m_index;
+  DataSource m_dataSource;
   traffic::TrafficCache m_trafficCache;
 
   std::vector<platform::LocalCountryFile> m_localFiles;
diff --git a/routing/routing_integration_tests/get_altitude_test.cpp b/routing/routing_integration_tests/get_altitude_test.cpp
index 525f08fcfc..bb561eea76 100644
--- a/routing/routing_integration_tests/get_altitude_test.cpp
+++ b/routing/routing_integration_tests/get_altitude_test.cpp
@@ -43,18 +43,18 @@ LocalCountryFile GetLocalCountryFileByCountryId(CountryFile const & country)
 void TestAltitudeOfAllMwmFeatures(string const & countryId, TAltitude const altitudeLowerBoundMeters,
                                   TAltitude const altitudeUpperBoundMeters)
 {
-  DataSource index;
+  DataSource dataSource;
 
   LocalCountryFile const country = GetLocalCountryFileByCountryId(CountryFile(countryId));
   TEST_NOT_EQUAL(country, LocalCountryFile(), ());
   TEST_NOT_EQUAL(country.GetFiles(), MapOptions::Nothing, (country));
 
-  pair<MwmSet::MwmId, MwmSet::RegResult> const regResult = index.RegisterMap(country);
+  pair<MwmSet::MwmId, MwmSet::RegResult> const regResult = dataSource.RegisterMap(country);
   TEST_EQUAL(regResult.second, MwmSet::RegResult::Success, ());
   TEST(regResult.first.IsAlive(), ());
 
   unique_ptr<AltitudeLoader> altitudeLoader =
-      make_unique<AltitudeLoader>(index, regResult.first /* mwmId */);
+      make_unique<AltitudeLoader>(dataSource, regResult.first /* mwmId */);
 
   classificator::Load();
   classif().SortClassificator();
diff --git a/routing/routing_integration_tests/road_graph_tests.cpp b/routing/routing_integration_tests/road_graph_tests.cpp
index c2e990c361..ebac0badeb 100644
--- a/routing/routing_integration_tests/road_graph_tests.cpp
+++ b/routing/routing_integration_tests/road_graph_tests.cpp
@@ -31,14 +31,14 @@ UNIT_TEST(FakeEdgesCombinatorialExplosion)
   GetAllLocalFiles(localFiles);
   TEST(!localFiles.empty(), ());
 
-  DataSource index;
+  DataSource dataSource;
   for (auto const & file : localFiles)
   {
-    auto const result = index.Register(file);
+    auto const result = dataSource.Register(file);
     TEST_EQUAL(result.second, MwmSet::RegResult::Success, ());
   }
 
-  FeaturesRoadGraph graph(index, IRoadGraph::Mode::ObeyOnewayTag,
+  FeaturesRoadGraph graph(dataSource, IRoadGraph::Mode::ObeyOnewayTag,
                           make_shared<CarModelFactory>(CountryParentNameGetterFn()));
   Junction const j(m2::PointD(MercatorBounds::FromLatLon(50.73208, -1.21279)), feature::kDefaultAltitudeMeters);
   std::vector<std::pair<routing::Edge, routing::Junction>> sourceVicinity;
diff --git a/routing/routing_integration_tests/routing_test_tools.cpp b/routing/routing_integration_tests/routing_test_tools.cpp
index 46931f03ff..8a4275689c 100644
--- a/routing/routing_integration_tests/routing_test_tools.cpp
+++ b/routing/routing_integration_tests/routing_test_tools.cpp
@@ -41,7 +41,7 @@ using namespace routing;
 using namespace routing_test;
 
 using TRouterFactory =
-    function<unique_ptr<IRouter>(DataSourceBase & index, TCountryFileFn const & countryFileFn,
+    function<unique_ptr<IRouter>(DataSourceBase & dataSource, TCountryFileFn const & countryFileFn,
                                  shared_ptr<NumMwmIds> numMwmIds)>;
 
 namespace
@@ -85,7 +85,7 @@ namespace integration
     return storage::CountryInfoReader::CreateCountryInfoReader(platform);
   }
 
-  unique_ptr<IndexRouter> CreateVehicleRouter(DataSourceBase & index,
+  unique_ptr<IndexRouter> CreateVehicleRouter(DataSourceBase & dataSource,
                                               storage::CountryInfoGetter const & infoGetter,
                                               traffic::TrafficCache const & trafficCache,
                                               vector<LocalCountryFile> const & localFiles,
@@ -103,7 +103,7 @@ namespace integration
     for (auto const & f : localFiles)
     {
       auto const & countryFile = f.GetCountryFile();
-      auto const mwmId = index.GetMwmIdByCountryFile(countryFile);
+      auto const mwmId = dataSource.GetMwmIdByCountryFile(countryFile);
       CHECK(mwmId.IsAlive(), ());
       if (mwmId.GetInfo()->GetType() == MwmInfo::COUNTRY && countryFile.GetName() != "minsk-pass")
         numMwmIds->RegisterFile(countryFile);
@@ -115,12 +115,12 @@ namespace integration
     auto indexRouter = make_unique<IndexRouter>(vehicleType, false /* load altitudes*/,
                                                 *countryParentGetter, countryFileGetter,
                                                 getMwmRectByName, numMwmIds,
-                                                MakeNumMwmTree(*numMwmIds, infoGetter), trafficCache, index);
+                                                MakeNumMwmTree(*numMwmIds, infoGetter), trafficCache, dataSource);
 
     return indexRouter;
   }
 
-  unique_ptr<IRouter> CreateAStarRouter(DataSourceBase & index,
+  unique_ptr<IRouter> CreateAStarRouter(DataSourceBase & dataSource,
                                         storage::CountryInfoGetter const & infoGetter,
                                         vector<LocalCountryFile> const & localFiles,
                                         TRouterFactory const & routerFactory)
@@ -136,7 +136,7 @@ namespace integration
     for (auto const & file : localFiles)
       numMwmIds->RegisterFile(file.GetCountryFile());
 
-    unique_ptr<IRouter> router = routerFactory(index, countryFileGetter, numMwmIds);
+    unique_ptr<IRouter> router = routerFactory(dataSource, countryFileGetter, numMwmIds);
     return unique_ptr<IRouter>(move(router));
   }
 
diff --git a/routing/routing_integration_tests/routing_test_tools.hpp b/routing/routing_integration_tests/routing_test_tools.hpp
index 6c659f7da9..88da715494 100644
--- a/routing/routing_integration_tests/routing_test_tools.hpp
+++ b/routing/routing_integration_tests/routing_test_tools.hpp
@@ -51,7 +51,7 @@ shared_ptr<model::FeaturesFetcher> CreateFeaturesFetcher(vector<LocalCountryFile
 
 unique_ptr<storage::CountryInfoGetter> CreateCountryInfoGetter();
 
-unique_ptr<IndexRouter> CreateVehicleRouter(DataSourceBase & index,
+unique_ptr<IndexRouter> CreateVehicleRouter(DataSourceBase & dataSource,
                                             storage::CountryInfoGetter const & infoGetter,
                                             traffic::TrafficCache const & trafficCache,
                                             vector<LocalCountryFile> const & localFiles,
@@ -81,7 +81,7 @@ class VehicleRouterComponents : public IRouterComponents
 public:
   VehicleRouterComponents(vector<LocalCountryFile> const & localFiles, VehicleType vehicleType)
     : IRouterComponents(localFiles)
-    , m_indexRouter(CreateVehicleRouter(m_featuresFetcher->GetIndex(), *m_infoGetter, m_trafficCache,
+    , m_indexRouter(CreateVehicleRouter(m_featuresFetcher->GetDataSource(), *m_infoGetter, m_trafficCache,
                                         localFiles, vehicleType))
   {
   }
diff --git a/routing/routing_session.cpp b/routing/routing_session.cpp
index fcd91502a3..e8a26acd98 100644
--- a/routing/routing_session.cpp
+++ b/routing/routing_session.cpp
@@ -285,7 +285,7 @@ void RoutingSession::ResetImpl()
 }
 
 RoutingSession::State RoutingSession::OnLocationPositionChanged(GpsInfo const & info,
-                                                                DataSourceBase const & index)
+                                                                DataSourceBase const & dataSource)
 {
   threads::MutexGuard guard(m_routingSessionMutex);
   ASSERT(m_state != RoutingNotActive, ());
@@ -328,7 +328,7 @@ RoutingSession::State RoutingSession::OnLocationPositionChanged(GpsInfo const &
         double const warningDistanceM = max(kSpeedCameraMinimalWarningMeters,
                                             info.m_speed * kSpeedCameraWarningSeconds);
         SpeedCameraRestriction cam(0, 0);
-        double const camDistance = GetDistanceToCurrentCamM(cam, index);
+        double const camDistance = GetDistanceToCurrentCamM(cam, dataSource);
         if (kInvalidSpeedCameraDistance != camDistance && camDistance < warningDistanceM)
         {
           if (cam.m_index > m_lastWarnedSpeedCameraIndex && info.m_speed > cam.m_maxSpeedKmH * kKmHToMps)
@@ -663,7 +663,7 @@ string RoutingSession::GetTurnNotificationsLocale() const
   return m_turnNotificationsMgr.GetLocale();
 }
 
-double RoutingSession::GetDistanceToCurrentCamM(SpeedCameraRestriction & camera, DataSourceBase const & index)
+double RoutingSession::GetDistanceToCurrentCamM(SpeedCameraRestriction & camera, DataSourceBase const & dataSource)
 {
   ASSERT(m_route, ());
 
@@ -679,7 +679,7 @@ double RoutingSession::GetDistanceToCurrentCamM(SpeedCameraRestriction & camera,
   size_t const upperBound = min(m_poly.GetPolyline().GetSize(), currentIndex + kSpeedCameraLookAheadCount);
   for (m_lastCheckedSpeedCameraIndex = currentIndex; m_lastCheckedSpeedCameraIndex < upperBound; ++m_lastCheckedSpeedCameraIndex)
   {
-    uint8_t speed = CheckCameraInPoint(m_poly.GetPolyline().GetPoint(m_lastCheckedSpeedCameraIndex), index);
+    uint8_t speed = CheckCameraInPoint(m_poly.GetPolyline().GetPoint(m_lastCheckedSpeedCameraIndex), dataSource);
     if (speed != kNoSpeedCamera)
     {
       camera = SpeedCameraRestriction(static_cast<uint32_t>(m_lastCheckedSpeedCameraIndex), speed);
diff --git a/routing/routing_session.hpp b/routing/routing_session.hpp
index 07b3391a9a..505576166e 100644
--- a/routing/routing_session.hpp
+++ b/routing/routing_session.hpp
@@ -120,7 +120,7 @@ public:
   bool GetRouteAltitudesAndDistancesM(vector<double> & routeSegDistanceM,
                                       feature::TAltitudes & routeAltitudesM) const;
 
-  State OnLocationPositionChanged(location::GpsInfo const & info, DataSourceBase const & index);
+  State OnLocationPositionChanged(location::GpsInfo const & info, DataSourceBase const & dataSource);
   void GetRouteFollowingInfo(location::FollowingInfo & info) const;
 
   void MatchLocationToRoute(location::GpsInfo & location,
@@ -191,7 +191,7 @@ private:
   /// Returns a nearest speed camera record on your way and distance to it.
   /// Returns kInvalidSpeedCameraDistance if there is no cameras on your way.
   // Should be called with locked m_routingSessionMutex.
-  double GetDistanceToCurrentCamM(SpeedCameraRestriction & camera, DataSourceBase const & index);
+  double GetDistanceToCurrentCamM(SpeedCameraRestriction & camera, DataSourceBase const & dataSource);
 
   /// RemoveRoute removes m_route and resets route attributes (m_state, m_lastDistance, m_moveAwayCounter).
   void RemoveRoute();
diff --git a/routing/routing_tests/routing_session_test.cpp b/routing/routing_tests/routing_session_test.cpp
index 72533be249..bdd5761b91 100644
--- a/routing/routing_tests/routing_session_test.cpp
+++ b/routing/routing_tests/routing_session_test.cpp
@@ -114,7 +114,7 @@ UNIT_TEST(TestRouteBuilding)
 
 UNIT_TEST(TestRouteRebuilding)
 {
-  DataSource index;
+  DataSource dataSource;
   RoutingSession session;
   session.Init(nullptr, nullptr);
   vector<m2::PointD> routePoints = kTestRoute;
@@ -144,7 +144,7 @@ UNIT_TEST(TestRouteRebuilding)
   RoutingSession::State code;
   while (info.m_latitude < kTestRoute.back().y)
   {
-    code = session.OnLocationPositionChanged(info, index);
+    code = session.OnLocationPositionChanged(info, dataSource);
     TEST_EQUAL(code, RoutingSession::State::OnRoute, ());
     info.m_latitude += 0.01;
   }
@@ -164,7 +164,7 @@ UNIT_TEST(TestRouteRebuilding)
   info.m_latitude = 1.;
   for (size_t i = 0; i < 10; ++i)
   {
-    code = session.OnLocationPositionChanged(info, index);
+    code = session.OnLocationPositionChanged(info, dataSource);
     info.m_latitude -= 0.1;
   }
   TEST_EQUAL(code, RoutingSession::State::RouteNeedRebuild, ());
@@ -172,7 +172,7 @@ UNIT_TEST(TestRouteRebuilding)
 
 UNIT_TEST(TestFollowRouteFlagPersistence)
 {
-  DataSource index;
+  DataSource dataSource;
   RoutingSession session;
   session.Init(nullptr, nullptr);
   vector<m2::PointD> routePoints = kTestRoute;
@@ -206,7 +206,7 @@ UNIT_TEST(TestFollowRouteFlagPersistence)
   RoutingSession::State code;
   while (info.m_latitude < kTestRoute.back().y)
   {
-    session.OnLocationPositionChanged(info, index);
+    session.OnLocationPositionChanged(info, dataSource);
     TEST(session.IsOnRoute() , ());
     TEST(session.IsFollowing(), ());
     info.m_latitude += 0.01;
@@ -231,7 +231,7 @@ UNIT_TEST(TestFollowRouteFlagPersistence)
   info.m_latitude = 1.;
   for (size_t i = 0; i < 10; ++i)
   {
-    code = session.OnLocationPositionChanged(info, index);
+    code = session.OnLocationPositionChanged(info, dataSource);
     info.m_latitude -= 0.1;
   }
   TEST_EQUAL(code, RoutingSession::State::RouteNeedRebuild, ());
@@ -248,7 +248,7 @@ UNIT_TEST(TestFollowRouteFlagPersistence)
 
 UNIT_TEST(TestFollowRoutePercentTest)
 {
-  DataSource index;
+  DataSource dataSource;
   RoutingSession session;
   session.Init(nullptr, nullptr);
   vector<m2::PointD> routePoints = kTestRoute;
@@ -282,23 +282,23 @@ UNIT_TEST(TestFollowRoutePercentTest)
   // Go through the route.
   info.m_longitude = 0.;
   info.m_latitude = 1.;
-  session.OnLocationPositionChanged(info, index);
+  session.OnLocationPositionChanged(info, dataSource);
   TEST(my::AlmostEqualAbs(session.GetCompletionPercent(), 0., 0.5), ());
 
   info.m_longitude = 0.;
   info.m_latitude = 2.;
-  session.OnLocationPositionChanged(info, index);
+  session.OnLocationPositionChanged(info, dataSource);
   TEST(my::AlmostEqualAbs(session.GetCompletionPercent(), 33.3, 0.5), ());
 
 
   info.m_longitude = 0.;
   info.m_latitude = 3.;
-  session.OnLocationPositionChanged(info, index);
+  session.OnLocationPositionChanged(info, dataSource);
   TEST(my::AlmostEqualAbs(session.GetCompletionPercent(), 66.6, 0.5), ());
 
   info.m_longitude = 0.;
   info.m_latitude = 3.99;
-  session.OnLocationPositionChanged(info, index);
+  session.OnLocationPositionChanged(info, dataSource);
   TEST(my::AlmostEqualAbs(session.GetCompletionPercent(), 100., 0.5), ());
 }
 }  // namespace routing
diff --git a/routing/speed_camera.cpp b/routing/speed_camera.cpp
index 233e6703df..2dcf4ac42f 100644
--- a/routing/speed_camera.cpp
+++ b/routing/speed_camera.cpp
@@ -37,12 +37,11 @@ uint8_t ReadCameraRestriction(FeatureType & ft)
   return 0;
 }
 
-uint8_t CheckCameraInPoint(m2::PointD const & point, DataSourceBase const & index)
+uint8_t CheckCameraInPoint(m2::PointD const & point, DataSourceBase const & dataSource)
 {
   uint32_t speedLimit = kNoSpeedCamera;
 
-  auto const f = [&point, &speedLimit](FeatureType & ft)
-  {
+  auto const f = [&point, &speedLimit](FeatureType & ft) {
     if (ft.GetFeatureType() != feature::GEOM_POINT)
       return;
 
@@ -55,10 +54,9 @@ uint8_t CheckCameraInPoint(m2::PointD const & point, DataSourceBase const & inde
       speedLimit = ReadCameraRestriction(ft);
   };
 
-  index.ForEachInRect(f,
-                      MercatorBounds::RectByCenterXYAndSizeInMeters(point,
-                                                                    kCameraCheckRadiusMeters),
-                      scales::GetUpperScale());
+  dataSource.ForEachInRect(
+      f, MercatorBounds::RectByCenterXYAndSizeInMeters(point, kCameraCheckRadiusMeters),
+      scales::GetUpperScale());
   return speedLimit;
 }
 }  // namespace routing
diff --git a/routing/speed_camera.hpp b/routing/speed_camera.hpp
index c6d27f0b40..175f84eefb 100644
--- a/routing/speed_camera.hpp
+++ b/routing/speed_camera.hpp
@@ -10,5 +10,5 @@ namespace routing
 {
 extern uint8_t const kNoSpeedCamera;
 
-uint8_t CheckCameraInPoint(m2::PointD const & point, DataSourceBase const & index);
+uint8_t CheckCameraInPoint(m2::PointD const & point, DataSourceBase const & dataSource);
 }  // namespace routing
diff --git a/routing/transit_graph_loader.cpp b/routing/transit_graph_loader.cpp
index 08fe4c892f..c55820f019 100644
--- a/routing/transit_graph_loader.cpp
+++ b/routing/transit_graph_loader.cpp
@@ -27,7 +27,7 @@ namespace routing
 class TransitGraphLoaderImpl : public TransitGraphLoader
 {
 public:
-  TransitGraphLoaderImpl(DataSourceBase & index, shared_ptr<NumMwmIds> numMwmIds,
+  TransitGraphLoaderImpl(DataSourceBase & dataSource, shared_ptr<NumMwmIds> numMwmIds,
                          shared_ptr<EdgeEstimator> estimator);
 
   // TransitGraphLoader overrides.
@@ -39,15 +39,15 @@ public:
 private:
   unique_ptr<TransitGraph> CreateTransitGraph(NumMwmId mwmId, IndexGraph & indexGraph) const;
 
-  DataSourceBase & m_index;
+  DataSourceBase & m_dataSource;
   shared_ptr<NumMwmIds> m_numMwmIds;
   shared_ptr<EdgeEstimator> m_estimator;
   unordered_map<NumMwmId, unique_ptr<TransitGraph>> m_graphs;
 };
 
-TransitGraphLoaderImpl::TransitGraphLoaderImpl(DataSourceBase & index, shared_ptr<NumMwmIds> numMwmIds,
+TransitGraphLoaderImpl::TransitGraphLoaderImpl(DataSourceBase & dataSource, shared_ptr<NumMwmIds> numMwmIds,
                                                shared_ptr<EdgeEstimator> estimator)
-  : m_index(index), m_numMwmIds(numMwmIds), m_estimator(estimator)
+  : m_dataSource(dataSource), m_numMwmIds(numMwmIds), m_estimator(estimator)
 {
 }
 
@@ -68,7 +68,7 @@ unique_ptr<TransitGraph> TransitGraphLoaderImpl::CreateTransitGraph(NumMwmId num
                                                                     IndexGraph & indexGraph) const
 {
   platform::CountryFile const & file = m_numMwmIds->GetFile(numMwmId);
-  MwmSet::MwmHandle handle = m_index.GetMwmHandleByCountryFile(file);
+  MwmSet::MwmHandle handle = m_dataSource.GetMwmHandleByCountryFile(file);
   if (!handle.IsAlive())
     MYTHROW(RoutingException, ("Can't get mwm handle for", file));
 
@@ -101,11 +101,11 @@ unique_ptr<TransitGraph> TransitGraphLoaderImpl::CreateTransitGraph(NumMwmId num
 }
 
 // static
-unique_ptr<TransitGraphLoader> TransitGraphLoader::Create(DataSourceBase & index,
+unique_ptr<TransitGraphLoader> TransitGraphLoader::Create(DataSourceBase & dataSource,
                                                           shared_ptr<NumMwmIds> numMwmIds,
                                                           shared_ptr<EdgeEstimator> estimator)
 {
-  return my::make_unique<TransitGraphLoaderImpl>(index, numMwmIds, estimator);
+  return my::make_unique<TransitGraphLoaderImpl>(dataSource, numMwmIds, estimator);
 }
 
 }  // namespace routing
diff --git a/routing/transit_graph_loader.hpp b/routing/transit_graph_loader.hpp
index e077b39848..a4fdbcdfb6 100644
--- a/routing/transit_graph_loader.hpp
+++ b/routing/transit_graph_loader.hpp
@@ -20,7 +20,7 @@ public:
   virtual TransitGraph & GetTransitGraph(NumMwmId mwmId, IndexGraph & indexGraph) = 0;
   virtual void Clear() = 0;
 
-  static std::unique_ptr<TransitGraphLoader> Create(DataSourceBase & index,
+  static std::unique_ptr<TransitGraphLoader> Create(DataSourceBase & dataSource,
                                                     std::shared_ptr<NumMwmIds> numMwmIds,
                                                     std::shared_ptr<EdgeEstimator> estimator);
 };
diff --git a/search/cities_boundaries_table.cpp b/search/cities_boundaries_table.cpp
index c6e4592485..55d9c39c2c 100644
--- a/search/cities_boundaries_table.cpp
+++ b/search/cities_boundaries_table.cpp
@@ -32,7 +32,7 @@ bool CitiesBoundariesTable::Boundaries::HasPoint(m2::PointD const & p) const
 // CitiesBoundariesTable ---------------------------------------------------------------------------
 bool CitiesBoundariesTable::Load()
 {
-  auto handle = FindWorld(m_index);
+  auto handle = FindWorld(m_dataSource);
   if (!handle.IsAlive())
   {
     LOG(LWARNING, ("Can't find World map file."));
diff --git a/search/cities_boundaries_table.hpp b/search/cities_boundaries_table.hpp
index e105ce5a54..7c1634ebe7 100644
--- a/search/cities_boundaries_table.hpp
+++ b/search/cities_boundaries_table.hpp
@@ -58,7 +58,7 @@ public:
     double m_eps = 0.0;
   };
 
-  explicit CitiesBoundariesTable(DataSourceBase const & index) : m_index(index) {}
+  explicit CitiesBoundariesTable(DataSourceBase const & dataSource) : m_dataSource(dataSource) {}
 
   bool Load();
 
@@ -69,7 +69,7 @@ public:
   bool Get(uint32_t fid, Boundaries & bs) const;
 
 private:
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   MwmSet::MwmId m_mwmId;
   std::unordered_map<uint32_t, std::vector<indexer::CityBoundary>> m_table;
   double m_eps = 0.0;
diff --git a/search/city_finder.cpp b/search/city_finder.cpp
index a94c6e74ad..be34025cbc 100644
--- a/search/city_finder.cpp
+++ b/search/city_finder.cpp
@@ -6,10 +6,10 @@ using namespace std;
 
 namespace search
 {
-CityFinder::CityFinder(DataSourceBase const & index)
-    : m_unusedBoundaries(index)
+CityFinder::CityFinder(DataSourceBase const & dataSource)
+    : m_unusedBoundaries(dataSource)
     , m_unusedCache(m_cancellable)
-    , m_finder(index, m_unusedBoundaries, m_unusedCache)
+    , m_finder(dataSource, m_unusedBoundaries, m_unusedCache)
 {
 }
 
diff --git a/search/city_finder.hpp b/search/city_finder.hpp
index f043372a32..f7b38f3e52 100644
--- a/search/city_finder.hpp
+++ b/search/city_finder.hpp
@@ -21,7 +21,7 @@ public:
   // TODO (@milchakov): consider to reuse locality finder from search
   // engine.  Otherwise, CityFinder won't benefit from approximated
   // cities boundaries.
-  explicit CityFinder(DataSourceBase const & index);
+  explicit CityFinder(DataSourceBase const & dataSource);
 
   std::string GetCityName(m2::PointD const & p, int8_t lang);
   FeatureID GetCityFeatureID(m2::PointD const & p);
diff --git a/search/downloader_search_callback.cpp b/search/downloader_search_callback.cpp
index 3988444243..a965aaf065 100644
--- a/search/downloader_search_callback.cpp
+++ b/search/downloader_search_callback.cpp
@@ -35,12 +35,12 @@ bool GetGroupCountryIdFromFeature(storage::Storage const & storage, FeatureType
 
 namespace search
 {
-DownloaderSearchCallback::DownloaderSearchCallback(Delegate & delegate, DataSourceBase const & index,
+DownloaderSearchCallback::DownloaderSearchCallback(Delegate & delegate, DataSourceBase const & dataSource,
                                                    storage::CountryInfoGetter const & infoGetter,
                                                    storage::Storage const & storage,
                                                    storage::DownloaderSearchParams params)
   : m_delegate(delegate)
-  , m_index(index)
+  , m_dataSource(dataSource)
   , m_infoGetter(infoGetter)
   , m_storage(storage)
   , m_params(move(params))
@@ -60,7 +60,7 @@ void DownloaderSearchCallback::operator()(search::Results const & results)
     if (result.GetResultType() != search::Result::Type::LatLon)
     {
       FeatureID const & fid = result.GetFeatureID();
-      EditableDataSource::FeaturesLoaderGuard loader(m_index, fid.m_mwmId);
+      EditableDataSource::FeaturesLoaderGuard loader(m_dataSource, fid.m_mwmId);
       FeatureType ft;
       if (!loader.GetFeatureByIndex(fid.m_index, ft))
       {
diff --git a/search/downloader_search_callback.hpp b/search/downloader_search_callback.hpp
index 9a8074218a..555b67fd58 100644
--- a/search/downloader_search_callback.hpp
+++ b/search/downloader_search_callback.hpp
@@ -30,7 +30,7 @@ public:
     virtual void RunUITask(std::function<void()> fn) = 0;
   };
 
-  DownloaderSearchCallback(Delegate & delegate, DataSourceBase const & index,
+  DownloaderSearchCallback(Delegate & delegate, DataSourceBase const & dataSource,
                            storage::CountryInfoGetter const & infoGetter,
                            storage::Storage const & storage,
                            storage::DownloaderSearchParams params);
@@ -39,7 +39,7 @@ public:
 
 private:
   Delegate & m_delegate;
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   storage::CountryInfoGetter const & m_infoGetter;
   storage::Storage const & m_storage;
   storage::DownloaderSearchParams m_params;
diff --git a/search/editor_delegate.cpp b/search/editor_delegate.cpp
index f60ce40d1c..7faf4c3463 100644
--- a/search/editor_delegate.cpp
+++ b/search/editor_delegate.cpp
@@ -9,16 +9,16 @@
 
 namespace search
 {
-EditorDelegate::EditorDelegate(DataSourceBase const & index) : m_index(index) {}
+EditorDelegate::EditorDelegate(DataSourceBase const & dataSource) : m_dataSource(dataSource) {}
 
 MwmSet::MwmId EditorDelegate::GetMwmIdByMapName(string const & name) const
 {
-  return m_index.GetMwmIdByCountryFile(platform::CountryFile(name));
+  return m_dataSource.GetMwmIdByCountryFile(platform::CountryFile(name));
 }
 
 unique_ptr<FeatureType> EditorDelegate::GetOriginalFeature(FeatureID const & fid) const
 {
-  EditableDataSource::FeaturesLoaderGuard guard(m_index, fid.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard guard(m_dataSource, fid.m_mwmId);
   auto feature = guard.GetOriginalFeatureByIndex(fid.m_index);
   if (feature)
     feature->ParseEverything();
@@ -28,7 +28,7 @@ unique_ptr<FeatureType> EditorDelegate::GetOriginalFeature(FeatureID const & fid
 
 string EditorDelegate::GetOriginalFeatureStreet(FeatureType & ft) const
 {
-  search::ReverseGeocoder const coder(m_index);
+  search::ReverseGeocoder const coder(m_dataSource);
   auto const streets = coder.GetNearbyFeatureStreets(ft);
   if (streets.second < streets.first.size())
     return streets.first[streets.second].m_name;
@@ -39,6 +39,6 @@ void EditorDelegate::ForEachFeatureAtPoint(osm::Editor::FeatureTypeFn && fn,
                                            m2::PointD const & point) const
 {
   auto const kToleranceMeters = 1e-2;
-  indexer::ForEachFeatureAtPoint(m_index, move(fn), point, kToleranceMeters);
+  indexer::ForEachFeatureAtPoint(m_dataSource, move(fn), point, kToleranceMeters);
 }
 }  // namespace search
diff --git a/search/editor_delegate.hpp b/search/editor_delegate.hpp
index 4a98743a42..333e500012 100644
--- a/search/editor_delegate.hpp
+++ b/search/editor_delegate.hpp
@@ -9,7 +9,7 @@ namespace search
 class EditorDelegate : public osm::Editor::Delegate
 {
 public:
-  EditorDelegate(DataSourceBase const & index);
+  EditorDelegate(DataSourceBase const & dataSource);
 
   // osm::Editor::Delegate overrides:
   MwmSet::MwmId GetMwmIdByMapName(string const & name) const override;
@@ -19,6 +19,6 @@ public:
                              m2::PointD const & point) const override;
 
 private:
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
 };
 }  // namespace search
diff --git a/search/engine.cpp b/search/engine.cpp
index e9c08a2dea..f3a559cc2c 100644
--- a/search/engine.cpp
+++ b/search/engine.cpp
@@ -92,7 +92,7 @@ Engine::Params::Params(string const & locale, size_t numThreads)
 }
 
 // Engine ------------------------------------------------------------------------------------------
-Engine::Engine(DataSourceBase & index, CategoriesHolder const & categories,
+Engine::Engine(DataSourceBase & dataSource, CategoriesHolder const & categories,
                storage::CountryInfoGetter const & infoGetter, Params const & params)
   : m_shutdown(false)
 {
@@ -103,7 +103,7 @@ Engine::Engine(DataSourceBase & index, CategoriesHolder const & categories,
   m_contexts.resize(params.m_numThreads);
   for (size_t i = 0; i < params.m_numThreads; ++i)
   {
-    auto processor = make_unique<Processor>(index, categories, m_suggests, infoGetter);
+    auto processor = make_unique<Processor>(dataSource, categories, m_suggests, infoGetter);
     processor->SetPreferredLocale(params.m_locale);
     m_contexts[i].m_processor = move(processor);
   }
diff --git a/search/engine.hpp b/search/engine.hpp
index edc4430f53..ec5beb030c 100644
--- a/search/engine.hpp
+++ b/search/engine.hpp
@@ -89,8 +89,8 @@ public:
     size_t m_numThreads;
   };
 
-  // Doesn't take ownership of index and categories.
-  Engine(DataSourceBase & index, CategoriesHolder const & categories,
+  // Doesn't take ownership of dataSource and categories.
+  Engine(DataSourceBase & dataSource, CategoriesHolder const & categories,
          storage::CountryInfoGetter const & infoGetter, Params const & params);
   ~Engine();
 
diff --git a/search/feature_loader.cpp b/search/feature_loader.cpp
index 10fabe1949..9841aa4b26 100644
--- a/search/feature_loader.cpp
+++ b/search/feature_loader.cpp
@@ -6,7 +6,7 @@
 
 namespace search
 {
-FeatureLoader::FeatureLoader(DataSourceBase const & index) : m_index(index) {}
+FeatureLoader::FeatureLoader(DataSourceBase const & dataSource) : m_dataSource(dataSource) {}
 
 bool FeatureLoader::Load(FeatureID const & id, FeatureType & ft)
 {
@@ -14,7 +14,7 @@ bool FeatureLoader::Load(FeatureID const & id, FeatureType & ft)
 
   auto const & mwmId = id.m_mwmId;
   if (!m_guard || m_guard->GetId() != mwmId)
-    m_guard = my::make_unique<EditableDataSource::FeaturesLoaderGuard>(m_index, mwmId);
+    m_guard = my::make_unique<EditableDataSource::FeaturesLoaderGuard>(m_dataSource, mwmId);
   return m_guard->GetFeatureByIndex(id.m_index, ft);
 }
 
diff --git a/search/feature_loader.hpp b/search/feature_loader.hpp
index 4ab62f94cb..5d79a326e0 100644
--- a/search/feature_loader.hpp
+++ b/search/feature_loader.hpp
@@ -19,7 +19,7 @@ namespace search
 class FeatureLoader
 {
 public:
-  explicit FeatureLoader(DataSourceBase const & index);
+  explicit FeatureLoader(DataSourceBase const & dataSource);
 
   WARN_UNUSED_RESULT bool Load(FeatureID const & id, FeatureType & ft);
 
@@ -28,11 +28,11 @@ public:
   void ForEachInRect(m2::RectD const & rect, std::function<void(FeatureType &)> const & fn)
   {
     ASSERT(m_checker.CalledOnOriginalThread(), ());
-    m_index.ForEachInRect(fn, rect, scales::GetUpperScale());
+    m_dataSource.ForEachInRect(fn, rect, scales::GetUpperScale());
   }
 
 private:
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   std::unique_ptr<EditableDataSource::FeaturesLoaderGuard> m_guard;
 
   ThreadChecker m_checker;
diff --git a/search/features_layer_matcher.cpp b/search/features_layer_matcher.cpp
index c82efd6111..b7974aaa00 100644
--- a/search/features_layer_matcher.cpp
+++ b/search/features_layer_matcher.cpp
@@ -13,11 +13,11 @@ namespace search
 /// even if there is no exact street written for this house.
 int constexpr kMaxApproxStreetDistanceM = 100;
 
-FeaturesLayerMatcher::FeaturesLayerMatcher(DataSourceBase const & index,
+FeaturesLayerMatcher::FeaturesLayerMatcher(DataSourceBase const & dataSource,
                                            ::base::Cancellable const & cancellable)
   : m_context(nullptr)
   , m_postcodes(nullptr)
-  , m_reverseGeocoder(index)
+  , m_reverseGeocoder(dataSource)
   , m_nearbyStreetsCache("FeatureToNearbyStreets")
   , m_matchingStreetsCache("BuildingToStreet")
   , m_loader(scales::GetUpperScale(), ReverseGeocoder::kLookupRadiusM)
diff --git a/search/features_layer_matcher.hpp b/search/features_layer_matcher.hpp
index 7742b6bb71..22aea70380 100644
--- a/search/features_layer_matcher.hpp
+++ b/search/features_layer_matcher.hpp
@@ -61,7 +61,7 @@ public:
   static int constexpr kBuildingRadiusMeters = 50;
   static int constexpr kStreetRadiusMeters = 100;
 
-  FeaturesLayerMatcher(DataSourceBase const & index, ::base::Cancellable const & cancellable);
+  FeaturesLayerMatcher(DataSourceBase const & dataSource, ::base::Cancellable const & cancellable);
   void SetContext(MwmContext * context);
   void SetPostcodes(CBV const * postcodes);
 
diff --git a/search/geocoder.cpp b/search/geocoder.cpp
index 0ee6a292f5..7a0624d963 100644
--- a/search/geocoder.cpp
+++ b/search/geocoder.cpp
@@ -336,10 +336,10 @@ size_t OrderCountries(m2::RectD const & pivot, vector<shared_ptr<MwmInfo>> & inf
 }  // namespace
 
 // Geocoder::Geocoder ------------------------------------------------------------------------------
-Geocoder::Geocoder(DataSourceBase const & index, storage::CountryInfoGetter const & infoGetter,
+Geocoder::Geocoder(DataSourceBase const & dataSource, storage::CountryInfoGetter const & infoGetter,
                    CategoriesHolder const & categories, PreRanker & preRanker,
                    VillagesCache & villagesCache, ::base::Cancellable const & cancellable)
-  : m_index(index)
+  : m_dataSource(dataSource)
   , m_infoGetter(infoGetter)
   , m_categories(categories)
   , m_streetsCache(cancellable)
@@ -414,7 +414,7 @@ void Geocoder::GoEverywhere()
     return;
 
   vector<shared_ptr<MwmInfo>> infos;
-  m_index.GetMwmsInfo(infos);
+  m_dataSource.GetMwmsInfo(infos);
 
   GoImpl(infos, false /* inViewport */);
 }
@@ -425,7 +425,7 @@ void Geocoder::GoInViewport()
     return;
 
   vector<shared_ptr<MwmInfo>> infos;
-  m_index.GetMwmsInfo(infos);
+  m_dataSource.GetMwmsInfo(infos);
 
   my::EraseIf(infos, [this](shared_ptr<MwmInfo> const & info)
               {
@@ -473,7 +473,7 @@ void Geocoder::GoImpl(vector<shared_ptr<MwmInfo>> & infos, bool inViewport)
     m_cities.clear();
     for (auto & regions : m_regions)
       regions.clear();
-    MwmSet::MwmHandle handle = FindWorld(m_index, infos);
+    MwmSet::MwmHandle handle = FindWorld(m_dataSource, infos);
     if (handle.IsAlive())
     {
       auto & value = *handle.GetValue<MwmValue>();
@@ -525,7 +525,7 @@ void Geocoder::GoImpl(vector<shared_ptr<MwmInfo>> & infos, bool inViewport)
     {
       it = m_matchersCache
                .insert(make_pair(m_context->GetId(),
-                                 my::make_unique<FeaturesLayerMatcher>(m_index, m_cancellable)))
+                                 my::make_unique<FeaturesLayerMatcher>(m_dataSource, m_cancellable)))
                .first;
     }
     m_matcher = it->second.get();
@@ -754,7 +754,7 @@ void Geocoder::ForEachCountry(vector<shared_ptr<MwmInfo>> const & infos, TFn &&
     if (info->GetType() == MwmInfo::COUNTRY && m_params.m_mode == Mode::Downloader)
       continue;
 
-    auto handle = m_index.GetMwmHandleById(MwmSet::MwmId(info));
+    auto handle = m_dataSource.GetMwmHandleById(MwmSet::MwmId(info));
     if (!handle.IsAlive())
       continue;
     auto & value = *handle.GetValue<MwmValue>();
diff --git a/search/geocoder.hpp b/search/geocoder.hpp
index f3985b19af..0d280c9e3f 100644
--- a/search/geocoder.hpp
+++ b/search/geocoder.hpp
@@ -87,7 +87,7 @@ public:
     shared_ptr<Tracer> m_tracer;
   };
 
-  Geocoder(DataSourceBase const & index, storage::CountryInfoGetter const & infoGetter,
+  Geocoder(DataSourceBase const & dataSource, storage::CountryInfoGetter const & infoGetter,
            CategoriesHolder const & categories, PreRanker & preRanker,
            VillagesCache & villagesCache, ::base::Cancellable const & cancellable);
   ~Geocoder();
@@ -239,7 +239,7 @@ private:
   WARN_UNUSED_RESULT bool GetTypeInGeocoding(BaseContext const & ctx, uint32_t featureId,
                                              Model::Type & type);
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   storage::CountryInfoGetter const & m_infoGetter;
   CategoriesHolder const & m_categories;
 
diff --git a/search/house_detector.cpp b/search/house_detector.cpp
index e540198a3b..3000b356d9 100644
--- a/search/house_detector.cpp
+++ b/search/house_detector.cpp
@@ -294,8 +294,8 @@ void Street::SortHousesProjection()
   sort(m_houses.begin(), m_houses.end(), &LessStreetDistance);
 }
 
-HouseDetector::HouseDetector(DataSourceBase const & index)
-  : m_loader(index), m_streetNum(0)
+HouseDetector::HouseDetector(DataSourceBase const & dataSource)
+  : m_loader(dataSource), m_streetNum(0)
 {
   // default value for conversions
   SetMetres2Mercator(360.0 / 40.0E06);
diff --git a/search/house_detector.hpp b/search/house_detector.hpp
index 2062886f8e..8e72cdb43b 100644
--- a/search/house_detector.hpp
+++ b/search/house_detector.hpp
@@ -237,7 +237,7 @@ class HouseDetector
   double GetApprLengthMeters(int index) const;
 
 public:
-  HouseDetector(DataSourceBase const & index);
+  HouseDetector(DataSourceBase const & dataSource);
   ~HouseDetector();
 
   int LoadStreets(vector<FeatureID> const & ids);
diff --git a/search/locality_finder.cpp b/search/locality_finder.cpp
index 67d80f58dc..1d01c12605 100644
--- a/search/locality_finder.cpp
+++ b/search/locality_finder.cpp
@@ -206,9 +206,9 @@ void LocalityFinder::Holder::Clear()
 }
 
 // LocalityFinder ----------------------------------------------------------------------------------
-LocalityFinder::LocalityFinder(DataSourceBase const & index, CitiesBoundariesTable const & boundariesTable,
+LocalityFinder::LocalityFinder(DataSourceBase const & dataSource, CitiesBoundariesTable const & boundariesTable,
                                VillagesCache & villagesCache)
-  : m_index(index)
+  : m_dataSource(dataSource)
   , m_boundariesTable(boundariesTable)
   , m_villagesCache(villagesCache)
   , m_cities(kMaxCityRadiusMeters)
@@ -237,7 +237,7 @@ void LocalityFinder::LoadVicinity(m2::PointD const & p, bool loadCities, bool lo
   if (loadCities)
   {
     m2::RectD const crect = m_cities.GetDRect(p);
-    auto handle = m_index.GetMwmHandleById(m_worldId);
+    auto handle = m_dataSource.GetMwmHandleById(m_worldId);
     if (handle.IsAlive())
     {
       auto const & value = *handle.GetValue<MwmValue>();
@@ -258,7 +258,7 @@ void LocalityFinder::LoadVicinity(m2::PointD const & p, bool loadCities, bool lo
   {
     m2::RectD const vrect = m_villages.GetDRect(p);
     m_maps.ForEachInRect(m2::RectD(p, p), [&](MwmSet::MwmId const & id) {
-      auto handle = m_index.GetMwmHandleById(id);
+      auto handle = m_dataSource.GetMwmHandleById(id);
       if (!handle.IsAlive())
         return;
 
@@ -278,7 +278,7 @@ void LocalityFinder::UpdateMaps()
     return;
 
   vector<shared_ptr<MwmInfo>> mwmsInfo;
-  m_index.GetMwmsInfo(mwmsInfo);
+  m_dataSource.GetMwmsInfo(mwmsInfo);
   for (auto const & info : mwmsInfo)
   {
     MwmSet::MwmId id(info);
diff --git a/search/locality_finder.hpp b/search/locality_finder.hpp
index 640b304fc2..371e69f66a 100644
--- a/search/locality_finder.hpp
+++ b/search/locality_finder.hpp
@@ -100,7 +100,7 @@ public:
     DISALLOW_COPY_AND_MOVE(Holder);
   };
 
-  LocalityFinder(DataSourceBase const & index, CitiesBoundariesTable const & boundaries,
+  LocalityFinder(DataSourceBase const & dataSource, CitiesBoundariesTable const & boundaries,
                  VillagesCache & villagesCache);
 
   template <typename Fn>
@@ -125,7 +125,7 @@ private:
   void LoadVicinity(m2::PointD const & p, bool loadCities, bool loadVillages);
   void UpdateMaps();
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   CitiesBoundariesTable const & m_boundariesTable;
   VillagesCache & m_villagesCache;
 
diff --git a/search/nested_rects_cache.cpp b/search/nested_rects_cache.cpp
index a3e2b8b294..d7d53ab67b 100644
--- a/search/nested_rects_cache.cpp
+++ b/search/nested_rects_cache.cpp
@@ -19,8 +19,8 @@ namespace
 double const kPositionToleranceMeters = 15.0;
 }  // namespace
 
-NestedRectsCache::NestedRectsCache(DataSourceBase const & index)
-  : m_index(index), m_scale(0), m_position(0, 0), m_valid(false)
+NestedRectsCache::NestedRectsCache(DataSourceBase const & dataSource)
+  : m_dataSource(dataSource), m_scale(0), m_position(0, 0), m_valid(false)
 {
 }
 
@@ -107,7 +107,7 @@ void NestedRectsCache::Update()
       }
       lastFeatures->push_back(id.m_index);
     };
-    m_index.ForEachFeatureIDInRect(addId, rect, m_scale);
+    m_dataSource.ForEachFeatureIDInRect(addId, rect, m_scale);
     for (auto & kv : bucket)
       sort(kv.second.begin(), kv.second.end());
   }
diff --git a/search/nested_rects_cache.hpp b/search/nested_rects_cache.hpp
index 02b38acb18..10944797b2 100644
--- a/search/nested_rects_cache.hpp
+++ b/search/nested_rects_cache.hpp
@@ -14,7 +14,7 @@ namespace search
 class NestedRectsCache
 {
 public:
-  explicit NestedRectsCache(DataSourceBase const & index);
+  explicit NestedRectsCache(DataSourceBase const & dataSource);
 
   void SetPosition(m2::PointD const & position, int scale);
 
@@ -37,7 +37,7 @@ private:
 
   void Update();
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   int m_scale;
   m2::PointD m_position;
   bool m_valid;
diff --git a/search/pre_ranker.cpp b/search/pre_ranker.cpp
index 9a04c66a4d..5d7a7ccd33 100644
--- a/search/pre_ranker.cpp
+++ b/search/pre_ranker.cpp
@@ -45,8 +45,8 @@ void SweepNearbyResults(double eps, set<FeatureID> const & prevEmit, vector<PreR
 }
 }  // namespace
 
-PreRanker::PreRanker(DataSourceBase const & index, Ranker & ranker)
-  : m_index(index), m_ranker(ranker), m_pivotFeatures(index)
+PreRanker::PreRanker(DataSourceBase const & dataSource, Ranker & ranker)
+  : m_dataSource(dataSource), m_ranker(ranker), m_pivotFeatures(dataSource)
 {
 }
 
@@ -81,7 +81,7 @@ void PreRanker::FillMissingFieldsInPreResults()
     if (id.m_mwmId != mwmId)
     {
       mwmId = id.m_mwmId;
-      mwmHandle = m_index.GetMwmHandleById(mwmId);
+      mwmHandle = m_dataSource.GetMwmHandleById(mwmId);
       ranks.reset();
       centers.reset();
       if (mwmHandle.IsAlive())
diff --git a/search/pre_ranker.hpp b/search/pre_ranker.hpp
index e6abddd8e0..ed62685036 100644
--- a/search/pre_ranker.hpp
+++ b/search/pre_ranker.hpp
@@ -50,7 +50,7 @@ public:
     bool m_viewportSearch = false;
   };
 
-  PreRanker(DataSourceBase const & index, Ranker & ranker);
+  PreRanker(DataSourceBase const & dataSource, Ranker & ranker);
 
   void Init(Params const & params);
 
@@ -89,7 +89,7 @@ public:
 private:
   void FilterForViewportSearch();
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   Ranker & m_ranker;
   vector<PreRankerResult> m_results;
   Params m_params;
diff --git a/search/processor.cpp b/search/processor.cpp
index ceb23c0f34..fd8052784a 100644
--- a/search/processor.cpp
+++ b/search/processor.cpp
@@ -141,19 +141,19 @@ size_t const Processor::kPreResultsCount = 200;
 double const Processor::kMinViewportRadiusM = 5.0 * 1000;
 double const Processor::kMaxViewportRadiusM = 50.0 * 1000;
 
-Processor::Processor(DataSourceBase const & index, CategoriesHolder const & categories,
+Processor::Processor(DataSourceBase const & dataSource, CategoriesHolder const & categories,
                      vector<Suggest> const & suggests,
                      storage::CountryInfoGetter const & infoGetter)
   : m_categories(categories)
   , m_infoGetter(infoGetter)
   , m_position(0, 0)
   , m_villagesCache(static_cast<::base::Cancellable const &>(*this))
-  , m_citiesBoundaries(index)
+  , m_citiesBoundaries(dataSource)
   , m_keywordsScorer(LanguageTier::LANGUAGE_TIER_COUNT)
-  , m_ranker(index, m_citiesBoundaries, infoGetter, m_keywordsScorer, m_emitter, categories,
+  , m_ranker(dataSource, m_citiesBoundaries, infoGetter, m_keywordsScorer, m_emitter, categories,
              suggests, m_villagesCache, static_cast<::base::Cancellable const &>(*this))
-  , m_preRanker(index, m_ranker)
-  , m_geocoder(index, infoGetter, categories, m_preRanker, m_villagesCache,
+  , m_preRanker(dataSource, m_ranker)
+  , m_geocoder(dataSource, infoGetter, categories, m_preRanker, m_villagesCache,
                static_cast<::base::Cancellable const &>(*this))
   , m_bookmarksProcessor(m_emitter, static_cast<::base::Cancellable const &>(*this))
 {
diff --git a/search/processor.hpp b/search/processor.hpp
index 522272d271..588058efa1 100644
--- a/search/processor.hpp
+++ b/search/processor.hpp
@@ -63,7 +63,7 @@ public:
   static double const kMinViewportRadiusM;
   static double const kMaxViewportRadiusM;
 
-  Processor(DataSourceBase const & index, CategoriesHolder const & categories,
+  Processor(DataSourceBase const & dataSource, CategoriesHolder const & categories,
             std::vector<Suggest> const & suggests, storage::CountryInfoGetter const & infoGetter);
 
   void SetViewport(m2::RectD const & viewport);
diff --git a/search/pysearch/bindings.cpp b/search/pysearch/bindings.cpp
index b3c93636ab..cf6208f2ed 100644
--- a/search/pysearch/bindings.cpp
+++ b/search/pysearch/bindings.cpp
@@ -184,9 +184,9 @@ unique_ptr<storage::CountryInfoGetter> CreateCountryInfoGetter()
 
 struct Context
 {
-  Context() : m_engine(m_index, CreateCountryInfoGetter(), search::Engine::Params{}) {}
+  Context() : m_engine(m_dataSource, CreateCountryInfoGetter(), search::Engine::Params{}) {}
 
-  DataSource m_index;
+  DataSource m_dataSource;
   search::tests_support::TestSearchEngine m_engine;
 };
 
@@ -200,7 +200,7 @@ struct SearchEngineProxy
     for (auto & mwm : mwms)
     {
       mwm.SyncWithDisk();
-      m_context->m_index.RegisterMap(mwm);
+      m_context->m_dataSource.RegisterMap(mwm);
     }
   }
 
diff --git a/search/rank_table_cache.cpp b/search/rank_table_cache.cpp
index 23d885d777..9af61e7aa9 100644
--- a/search/rank_table_cache.cpp
+++ b/search/rank_table_cache.cpp
@@ -7,13 +7,13 @@
 
 namespace search
 {
-RankTable const & RankTableCache::Get(DataSourceBase & index, TId const & mwmId)
+RankTable const & RankTableCache::Get(DataSourceBase & dataSource, TId const & mwmId)
 {
   auto const it = m_ranks.find(TKey(mwmId));
   if (it != m_ranks.end())
     return *it->second;
 
-  TKey handle(index.GetMwmHandleById(mwmId));
+  TKey handle(dataSource.GetMwmHandleById(mwmId));
   auto table = RankTable::Load(handle.GetValue<MwmValue>()->m_cont);
   if (!table)
     table.reset(new DummyRankTable());
diff --git a/search/rank_table_cache.hpp b/search/rank_table_cache.hpp
index 13b7d59979..c7b8d691ee 100644
--- a/search/rank_table_cache.hpp
+++ b/search/rank_table_cache.hpp
@@ -29,7 +29,7 @@ class RankTableCache
 public:
   RankTableCache() = default;
 
-  RankTable const & Get(DataSourceBase & index, TId const & mwmId);
+  RankTable const & Get(DataSourceBase & dataSource, TId const & mwmId);
 
   void Remove(TId const & id);
   void Clear();
diff --git a/search/ranker.cpp b/search/ranker.cpp
index b4c39cb4c8..1931b9dbb1 100644
--- a/search/ranker.cpp
+++ b/search/ranker.cpp
@@ -211,7 +211,7 @@ class RankerResultMaker
 {
   using LoaderGuard = EditableDataSource::FeaturesLoaderGuard;
   Ranker & m_ranker;
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   Geocoder::Params const & m_params;
   storage::CountryInfoGetter const & m_infoGetter;
 
@@ -220,7 +220,7 @@ class RankerResultMaker
   bool LoadFeature(FeatureID const & id, FeatureType & ft)
   {
     if (!m_loader || m_loader->GetId() != id.m_mwmId)
-      m_loader = make_unique<LoaderGuard>(m_index, id.m_mwmId);
+      m_loader = make_unique<LoaderGuard>(m_dataSource, id.m_mwmId);
     if (!m_loader->GetFeatureByIndex(id.m_index, ft))
       return false;
 
@@ -331,9 +331,9 @@ class RankerResultMaker
   }
 
 public:
-  RankerResultMaker(Ranker & ranker, DataSourceBase const & index,
+  RankerResultMaker(Ranker & ranker, DataSourceBase const & dataSource,
                     storage::CountryInfoGetter const & infoGetter, Geocoder::Params const & params)
-    : m_ranker(ranker), m_index(index), m_params(params), m_infoGetter(infoGetter)
+    : m_ranker(ranker), m_dataSource(dataSource), m_params(params), m_infoGetter(infoGetter)
   {
   }
 
@@ -358,16 +358,16 @@ public:
   }
 };
 
-Ranker::Ranker(DataSourceBase const & index, CitiesBoundariesTable const & boundariesTable,
+Ranker::Ranker(DataSourceBase const & dataSource, CitiesBoundariesTable const & boundariesTable,
                storage::CountryInfoGetter const & infoGetter, KeywordLangMatcher & keywordsScorer,
                Emitter & emitter, CategoriesHolder const & categories,
                vector<Suggest> const & suggests, VillagesCache & villagesCache,
                ::base::Cancellable const & cancellable)
-  : m_reverseGeocoder(index)
+  : m_reverseGeocoder(dataSource)
   , m_cancellable(cancellable)
   , m_keywordsScorer(keywordsScorer)
-  , m_localities(index, boundariesTable, villagesCache)
-  , m_index(index)
+  , m_localities(dataSource, boundariesTable, villagesCache)
+  , m_dataSource(dataSource)
   , m_infoGetter(infoGetter)
   , m_emitter(emitter)
   , m_categories(categories)
@@ -542,7 +542,7 @@ void Ranker::LoadCountriesTree() { m_regionInfoGetter.LoadCountriesTree(); }
 void Ranker::MakeRankerResults(Geocoder::Params const & geocoderParams,
                                vector<RankerResult> & results)
 {
-  RankerResultMaker maker(*this, m_index, m_infoGetter, geocoderParams);
+  RankerResultMaker maker(*this, m_dataSource, m_infoGetter, geocoderParams);
   for (auto const & r : m_preRankerResults)
   {
     auto p = maker(r);
diff --git a/search/ranker.hpp b/search/ranker.hpp
index 8bc4ecbb77..9cf11f09fd 100644
--- a/search/ranker.hpp
+++ b/search/ranker.hpp
@@ -79,7 +79,7 @@ public:
     size_t m_limit = 0;
   };
 
-  Ranker(DataSourceBase const & index, CitiesBoundariesTable const & boundariesTable,
+  Ranker(DataSourceBase const & dataSource, CitiesBoundariesTable const & boundariesTable,
          storage::CountryInfoGetter const & infoGetter, KeywordLangMatcher & keywordsScorer,
          Emitter & emitter, CategoriesHolder const & categories,
          std::vector<Suggest> const & suggests, VillagesCache & villagesCache,
@@ -134,7 +134,7 @@ private:
   int8_t m_localeCode;
   RegionInfoGetter m_regionInfoGetter;
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   storage::CountryInfoGetter const & m_infoGetter;
   Emitter & m_emitter;
   CategoriesHolder const & m_categories;
diff --git a/search/reverse_geocoder.cpp b/search/reverse_geocoder.cpp
index 8638dfd59b..33412e094c 100644
--- a/search/reverse_geocoder.cpp
+++ b/search/reverse_geocoder.cpp
@@ -24,7 +24,7 @@ int constexpr kQueryScale = scales::GetUpperScale();
 size_t constexpr kMaxNumTriesToApproxAddress = 10;
 } // namespace
 
-ReverseGeocoder::ReverseGeocoder(DataSourceBase const & index) : m_index(index) {}
+ReverseGeocoder::ReverseGeocoder(DataSourceBase const & dataSource) : m_dataSource(dataSource) {}
 
 void ReverseGeocoder::GetNearbyStreets(MwmSet::MwmId const & id, m2::PointD const & center,
                                        vector<Street> & streets) const
@@ -48,7 +48,7 @@ void ReverseGeocoder::GetNearbyStreets(MwmSet::MwmId const & id, m2::PointD cons
     streets.emplace_back(ft.GetID(), feature::GetMinDistanceMeters(ft, center), name);
   };
 
-  MwmSet::MwmHandle mwmHandle = m_index.GetMwmHandleById(id);
+  MwmSet::MwmHandle mwmHandle = m_dataSource.GetMwmHandleById(id);
   if (mwmHandle.IsAlive())
   {
     search::MwmContext(move(mwmHandle)).ForEachFeature(rect, addStreet);
@@ -102,7 +102,7 @@ ReverseGeocoder::GetNearbyFeatureStreets(FeatureType & ft) const
 
   GetNearbyStreets(ft, result.first);
 
-  HouseTable table(m_index);
+  HouseTable table(m_dataSource);
   if (!table.Get(ft.GetID(), result.second))
     result.second = numeric_limits<uint32_t>::max();
 
@@ -114,7 +114,7 @@ void ReverseGeocoder::GetNearbyAddress(m2::PointD const & center, Address & addr
   vector<Building> buildings;
   GetNearbyBuildings(center, buildings);
 
-  HouseTable table(m_index);
+  HouseTable table(m_dataSource);
   size_t triesCount = 0;
 
   for (auto const & b : buildings)
@@ -130,7 +130,7 @@ bool ReverseGeocoder::GetExactAddress(FeatureType const & ft, Address & addr) co
 {
   if (ft.GetHouseNumber().empty())
     return false;
-  HouseTable table(m_index);
+  HouseTable table(m_dataSource);
   return GetNearbyAddress(table, FromFeature(ft, 0.0 /* distMeters */), addr);
 }
 
@@ -174,7 +174,7 @@ void ReverseGeocoder::GetNearbyBuildings(m2::PointD const & center, vector<Build
       buildings.push_back(FromFeature(ft, feature::GetMinDistanceMeters(ft, center)));
   };
 
-  m_index.ForEachInRect(addBuilding, rect, kQueryScale);
+  m_dataSource.ForEachInRect(addBuilding, rect, kQueryScale);
   sort(buildings.begin(), buildings.end(), my::LessBy(&Building::m_distanceMeters));
 }
 
@@ -194,7 +194,7 @@ bool ReverseGeocoder::HouseTable::Get(FeatureID const & fid, uint32_t & streetIn
 {
   if (!m_table || m_handle.GetId() != fid.m_mwmId)
   {
-    m_handle = m_index.GetMwmHandleById(fid.m_mwmId);
+    m_handle = m_dataSource.GetMwmHandleById(fid.m_mwmId);
     if (!m_handle.IsAlive())
     {
       LOG(LWARNING, ("MWM", fid, "is dead"));
diff --git a/search/reverse_geocoder.hpp b/search/reverse_geocoder.hpp
index 794272ffc5..fe71871946 100644
--- a/search/reverse_geocoder.hpp
+++ b/search/reverse_geocoder.hpp
@@ -19,7 +19,7 @@ namespace search
 
 class ReverseGeocoder
 {
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
 
   struct Object
   {
@@ -42,7 +42,7 @@ public:
   /// All "Nearby" functions work in this lookup radius.
   static int constexpr kLookupRadiusM = 500;
 
-  explicit ReverseGeocoder(DataSourceBase const & index);
+  explicit ReverseGeocoder(DataSourceBase const & dataSource);
 
   using Street = Object;
 
@@ -98,11 +98,11 @@ private:
   /// Helper class to incapsulate house 2 street table reloading.
   class HouseTable
   {
-    DataSourceBase const & m_index;
+    DataSourceBase const & m_dataSource;
     unique_ptr<search::HouseToStreetTable> m_table;
     MwmSet::MwmHandle m_handle;
   public:
-    explicit HouseTable(DataSourceBase const & index) : m_index(index) {}
+    explicit HouseTable(DataSourceBase const & dataSource) : m_dataSource(dataSource) {}
     bool Get(FeatureID const & fid, uint32_t & streetIndex);
   };
 
diff --git a/search/search_integration_tests/downloader_search_test.cpp b/search/search_integration_tests/downloader_search_test.cpp
index da8e234648..7462a7ef39 100644
--- a/search/search_integration_tests/downloader_search_test.cpp
+++ b/search/search_integration_tests/downloader_search_test.cpp
@@ -106,10 +106,10 @@ public:
 class DownloaderSearchRequest : public TestSearchRequest, public TestDelegate
 {
 public:
-  DownloaderSearchRequest(DataSourceBase & index, TestSearchEngine & engine, string const & query)
+  DownloaderSearchRequest(DataSourceBase & dataSource, TestSearchEngine & engine, string const & query)
     : TestSearchRequest(engine, MakeSearchParams(query))
     , m_storage(kCountriesTxt, make_unique<TestMapFilesDownloader>())
-    , m_downloaderCallback(static_cast<DownloaderSearchCallback::Delegate &>(*this), index,
+    , m_downloaderCallback(static_cast<DownloaderSearchCallback::Delegate &>(*this), dataSource,
                            m_engine.GetCountryInfoGetter(), m_storage, MakeDownloaderParams(query))
   {
     SetCustomOnResults(bind(&DownloaderSearchRequest::OnResultsDownloader, this, placeholders::_1));
@@ -221,7 +221,7 @@ UNIT_CLASS_TEST(DownloaderSearchTest, Smoke)
   BuildWorld();
 
   {
-    DownloaderSearchRequest request(m_index, m_engine, "square one");
+    DownloaderSearchRequest request(m_dataSource, m_engine, "square one");
     request.Run();
 
     TestResults(request.GetResults(),
@@ -229,7 +229,7 @@ UNIT_CLASS_TEST(DownloaderSearchTest, Smoke)
   }
 
   {
-    DownloaderSearchRequest request(m_index, m_engine, "shortpondland");
+    DownloaderSearchRequest request(m_dataSource, m_engine, "shortpondland");
     request.Run();
 
     TestResults(request.GetResults(),
@@ -237,14 +237,14 @@ UNIT_CLASS_TEST(DownloaderSearchTest, Smoke)
   }
 
   {
-    DownloaderSearchRequest request(m_index, m_engine, "flatland");
+    DownloaderSearchRequest request(m_dataSource, m_engine, "flatland");
     request.Run();
 
     TestResults(request.GetResults(), {storage::DownloaderSearchResult("Flatland", "Flatland")});
   }
 
   {
-    DownloaderSearchRequest request(m_index, m_engine, "square");
+    DownloaderSearchRequest request(m_dataSource, m_engine, "square");
     request.Run();
 
     TestResults(request.GetResults(),
diff --git a/search/search_integration_tests/generate_tests.cpp b/search/search_integration_tests/generate_tests.cpp
index 2099365100..c645521a8a 100644
--- a/search/search_integration_tests/generate_tests.cpp
+++ b/search/search_integration_tests/generate_tests.cpp
@@ -63,8 +63,8 @@ UNIT_CLASS_TEST(GenerateTest, GenerateDeprecatedTypes)
     MakeFeature(builder, {"shop", "estate_agent"}, {2, 2});
   }
 
-  DataSource index;
-  TEST_EQUAL(index.Register(file).second, MwmSet::RegResult::Success, ());
+  DataSource dataSource;
+  TEST_EQUAL(dataSource.Register(file).second, MwmSet::RegResult::Success, ());
 
   // New types.
   StringIL arr[] = {{"shop"}, {"office"}};
@@ -79,7 +79,7 @@ UNIT_CLASS_TEST(GenerateTest, GenerateDeprecatedTypes)
     ++count;
     ft.ForEachType([&](uint32_t t) { TEST(types.count(t) > 0, (cl.GetReadableObjectName(t))); });
   };
-  index.ForEachInScale(fn, scales::GetUpperScale());
+  dataSource.ForEachInScale(fn, scales::GetUpperScale());
 
   TEST_EQUAL(count, 3, ());
 
diff --git a/search/search_integration_tests/pre_ranker_test.cpp b/search/search_integration_tests/pre_ranker_test.cpp
index dca92daf93..637e778590 100644
--- a/search/search_integration_tests/pre_ranker_test.cpp
+++ b/search/search_integration_tests/pre_ranker_test.cpp
@@ -52,11 +52,11 @@ namespace
 class TestRanker : public Ranker
 {
 public:
-  TestRanker(DataSourceBase & index, storage::CountryInfoGetter & infoGetter,
+  TestRanker(DataSourceBase & dataSource, storage::CountryInfoGetter & infoGetter,
              CitiesBoundariesTable const & boundariesTable, KeywordLangMatcher & keywordsScorer,
              Emitter & emitter, vector<Suggest> const & suggests, VillagesCache & villagesCache,
              ::base::Cancellable const & cancellable, vector<PreRankerResult> & results)
-    : Ranker(index, boundariesTable, infoGetter, keywordsScorer, emitter, GetDefaultCategories(),
+    : Ranker(dataSource, boundariesTable, infoGetter, keywordsScorer, emitter, GetDefaultCategories(),
              suggests, villagesCache, cancellable)
     , m_results(results)
   {
@@ -122,13 +122,13 @@ UNIT_CLASS_TEST(PreRankerTest, Smoke)
 
   vector<PreRankerResult> results;
   Emitter emitter;
-  CitiesBoundariesTable boundariesTable(m_index);
+  CitiesBoundariesTable boundariesTable(m_dataSource);
   VillagesCache villagesCache(m_cancellable);
   KeywordLangMatcher keywordsScorer(0 /* maxLanguageTiers */);
-  TestRanker ranker(m_index, m_engine.GetCountryInfoGetter(), boundariesTable, keywordsScorer,
+  TestRanker ranker(m_dataSource, m_engine.GetCountryInfoGetter(), boundariesTable, keywordsScorer,
                     emitter, m_suggests, villagesCache, m_cancellable, results);
 
-  PreRanker preRanker(m_index, ranker);
+  PreRanker preRanker(m_dataSource, ranker);
   PreRanker::Params params;
   params.m_viewport = kViewport;
   params.m_accuratePivotCenter = kPivot;
diff --git a/search/search_integration_tests/processor_test.cpp b/search/search_integration_tests/processor_test.cpp
index 0f471bb296..bf250247d2 100644
--- a/search/search_integration_tests/processor_test.cpp
+++ b/search/search_integration_tests/processor_test.cpp
@@ -587,7 +587,7 @@ UNIT_CLASS_TEST(ProcessorTest, TestPostcodes)
 
   // Tests that postcode is added to the search index.
   {
-    MwmContext context(m_index.GetMwmHandleById(countryId));
+    MwmContext context(m_dataSource.GetMwmHandleById(countryId));
     ::base::Cancellable cancellable;
 
     QueryParams params;
@@ -605,7 +605,7 @@ UNIT_CLASS_TEST(ProcessorTest, TestPostcodes)
     while (!features->GetBit(index))
       ++index;
 
-    EditableDataSource::FeaturesLoaderGuard loader(m_index, countryId);
+    EditableDataSource::FeaturesLoaderGuard loader(m_dataSource, countryId);
     FeatureType ft;
     TEST(loader.GetFeatureByIndex(::base::checked_cast<uint32_t>(index), ft), ());
 
@@ -702,7 +702,7 @@ UNIT_CLASS_TEST(ProcessorTest, TestCategories)
     TEST(ResultsMatch(request->Results(), rules), ());
     for (auto const & result : request->Results())
     {
-      EditableDataSource::FeaturesLoaderGuard loader(m_index, wonderlandId);
+      EditableDataSource::FeaturesLoaderGuard loader(m_dataSource, wonderlandId);
       FeatureType ft;
       TEST(loader.GetFeatureByIndex(result.GetFeatureID().m_index, ft), ());
 
@@ -1141,7 +1141,7 @@ UNIT_CLASS_TEST(ProcessorTest, CityBoundaryLoad)
     TEST(ResultsMatch("moscow", "en", rules), ());
   }
 
-  CitiesBoundariesTable table(m_index);
+  CitiesBoundariesTable table(m_dataSource);
   TEST(table.Load(), ());
   TEST(table.Has(0 /* fid */), ());
   TEST(!table.Has(10 /* fid */), ());
diff --git a/search/search_quality/assessment_tool/main_model.cpp b/search/search_quality/assessment_tool/main_model.cpp
index a749b1a708..822d839d2d 100644
--- a/search/search_quality/assessment_tool/main_model.cpp
+++ b/search/search_quality/assessment_tool/main_model.cpp
@@ -30,8 +30,8 @@ using namespace std;
 // MainModel ---------------------------------------------------------------------------------------
 MainModel::MainModel(Framework & framework)
   : m_framework(framework)
-  , m_index(m_framework.GetIndex())
-  , m_loader(m_index)
+  , m_dataSource(m_framework.GetDataSource())
+  , m_loader(m_dataSource)
   , m_contexts(
         [this](size_t sampleIndex, Edits::Update const & update) {
           OnUpdate(View::ResultType::Found, sampleIndex, update);
@@ -147,7 +147,7 @@ void MainModel::OnSampleSelected(int index)
       if (results.IsEndedNormal())
       {
         // Can't use m_loader here due to thread-safety issues.
-        search::FeatureLoader loader(m_index);
+        search::FeatureLoader loader(m_dataSource);
         search::Matcher matcher(loader);
 
         vector<search::Result> const actual(results.begin(), results.end());
diff --git a/search/search_quality/assessment_tool/main_model.hpp b/search/search_quality/assessment_tool/main_model.hpp
index d45aa717f0..00d3160590 100644
--- a/search/search_quality/assessment_tool/main_model.hpp
+++ b/search/search_quality/assessment_tool/main_model.hpp
@@ -64,7 +64,7 @@ private:
   void ForAnyMatchingEntry(Context & context, FeatureID const & id, Fn && fn);
 
   Framework & m_framework;
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   search::FeatureLoader m_loader;
 
   ContextList m_contexts;
diff --git a/search/search_quality/features_collector_tool/features_collector_tool.cpp b/search/search_quality/features_collector_tool/features_collector_tool.cpp
index a5ff890b6d..6b188678e9 100644
--- a/search/search_quality/features_collector_tool/features_collector_tool.cpp
+++ b/search/search_quality/features_collector_tool/features_collector_tool.cpp
@@ -152,7 +152,7 @@ int main(int argc, char * argv[])
   }
 
   classificator::Load();
-  DataSource index;
+  DataSource dataSource;
 
   vector<platform::LocalCountryFile> mwms;
   platform::FindAllLocalMapsAndCleanup(numeric_limits<int64_t>::max() /* the latest version */,
@@ -160,13 +160,13 @@ int main(int argc, char * argv[])
   for (auto & mwm : mwms)
   {
     mwm.SyncWithDisk();
-    index.RegisterMap(mwm);
+    dataSource.RegisterMap(mwm);
   }
 
-  TestSearchEngine engine(index, move(infoGetter), Engine::Params{});
+  TestSearchEngine engine(dataSource, move(infoGetter), Engine::Params{});
 
   vector<Stats> stats(samples.size());
-  FeatureLoader loader(index);
+  FeatureLoader loader(dataSource);
   Matcher matcher(loader);
 
   cout << "SampleId,";
diff --git a/search/search_quality/search_quality_tool/search_quality_tool.cpp b/search/search_quality/search_quality_tool/search_quality_tool.cpp
index 47f9fd9a1f..2a93578cd1 100644
--- a/search/search_quality/search_quality_tool/search_quality_tool.cpp
+++ b/search/search_quality/search_quality_tool/search_quality_tool.cpp
@@ -197,11 +197,11 @@ void Split(string const & s, char delim, vector<string> & parts)
 
 // Returns the position of the result that is expected to be found by geocoder completeness
 // tests in the |result| vector or -1 if it does not occur there.
-int FindResult(DataSourceBase & index, string const & mwmName, uint32_t const featureId, double const lat,
+int FindResult(DataSourceBase & dataSource, string const & mwmName, uint32_t const featureId, double const lat,
                double const lon, vector<Result> const & results)
 {
   CHECK_LESS_OR_EQUAL(results.size(), numeric_limits<int>::max(), ());
-  auto const mwmId = index.GetMwmIdByCountryFile(platform::CountryFile(mwmName));
+  auto const mwmId = dataSource.GetMwmIdByCountryFile(platform::CountryFile(mwmName));
   FeatureID const expectedFeatureId(mwmId, featureId);
   for (size_t i = 0; i < results.size(); ++i)
   {
@@ -279,7 +279,7 @@ void ParseCompletenessQuery(string & s, CompletenessQuery & q)
 // from |path|, executes them against the |engine| with viewport set to |viewport|
 // and reports the number of queries whose expected result is among the returned results.
 // Exact feature id is expected, but a close enough (lat, lon) is good too.
-void CheckCompleteness(string const & path, m2::RectD const & viewport, DataSourceBase & index,
+void CheckCompleteness(string const & path, m2::RectD const & viewport, DataSourceBase & dataSource,
                        TestSearchEngine & engine)
 {
   my::ScopedLogAbortLevelChanger const logAbortLevel(LCRITICAL);
@@ -322,7 +322,7 @@ void CheckCompleteness(string const & path, m2::RectD const & viewport, DataSour
 
     LOG(LDEBUG, (q.m_query, q.m_request->Results()));
     int pos =
-        FindResult(index, q.m_mwmName, q.m_featureId, q.m_lat, q.m_lon, q.m_request->Results());
+        FindResult(dataSource, q.m_mwmName, q.m_featureId, q.m_lat, q.m_lon, q.m_request->Results());
     if (pos >= 0)
       ++expectedResultsFound;
     if (pos == 0)
@@ -379,7 +379,7 @@ int main(int argc, char * argv[])
   params.m_locale = FLAGS_locale;
   params.m_numThreads = FLAGS_num_threads;
 
-  DataSource index;
+  DataSource dataSource;
 
   vector<platform::LocalCountryFile> mwms;
   if (!FLAGS_mwm_list_path.empty())
@@ -401,11 +401,11 @@ int main(int argc, char * argv[])
   {
     mwm.SyncWithDisk();
     cout << mwm.GetCountryName() << " " << ReadVersionFromHeader(mwm) << endl;
-    index.RegisterMap(mwm);
+    dataSource.RegisterMap(mwm);
   }
   cout << endl;
 
-  TestSearchEngine engine(index, move(infoGetter), params);
+  TestSearchEngine engine(dataSource, move(infoGetter), params);
 
   m2::RectD viewport;
   {
@@ -425,7 +425,7 @@ int main(int argc, char * argv[])
 
   if (!FLAGS_check_completeness.empty())
   {
-    CheckCompleteness(FLAGS_check_completeness, viewport, index, engine);
+    CheckCompleteness(FLAGS_check_completeness, viewport, dataSource, engine);
     return 0;
   }
 
diff --git a/search/search_tests/house_detector_tests.cpp b/search/search_tests/house_detector_tests.cpp
index ccfc9d3f26..3775ebab9d 100644
--- a/search/search_tests/house_detector_tests.cpp
+++ b/search/search_tests/house_detector_tests.cpp
@@ -187,67 +187,67 @@ UNIT_TEST(HS_StreetsMerge)
 {
   classificator::Load();
 
-  DataSource index;
+  DataSource dataSource;
   LocalCountryFile localFile(LocalCountryFile::MakeForTesting("minsk-pass"));
   // Clean indexes to avoid jenkins errors.
   platform::CountryIndexes::DeleteFromDisk(localFile);
 
-  auto const p = index.Register(localFile);
+  auto const p = dataSource.Register(localFile);
   TEST(p.first.IsAlive(), ());
   TEST_EQUAL(MwmSet::RegResult::Success, p.second, ());
 
   {
-    search::HouseDetector houser(index);
+    search::HouseDetector houser(dataSource);
     StreetIDsByName toDo;
     toDo.streetNames.push_back("улица Володарского");
-    index.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
+    dataSource.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
     houser.LoadStreets(toDo.GetFeatureIDs());
     TEST_EQUAL(houser.MergeStreets(), 1, ());
   }
 
   {
-    search::HouseDetector houser(index);
+    search::HouseDetector houser(dataSource);
     StreetIDsByName toDo;
     toDo.streetNames.push_back("Московская улица");
-    index.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
+    dataSource.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
     houser.LoadStreets(toDo.GetFeatureIDs());
     TEST_GREATER_OR_EQUAL(houser.MergeStreets(), 1, ());
     TEST_LESS_OR_EQUAL(houser.MergeStreets(), 3, ());
   }
 
   {
-    search::HouseDetector houser(index);
+    search::HouseDetector houser(dataSource);
     StreetIDsByName toDo;
     toDo.streetNames.push_back("проспект Независимости");
     toDo.streetNames.push_back("Московская улица");
-    index.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
+    dataSource.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
     houser.LoadStreets(toDo.GetFeatureIDs());
     TEST_GREATER_OR_EQUAL(houser.MergeStreets(), 1, ());
     TEST_LESS_OR_EQUAL(houser.MergeStreets(), 5, ());
   }
 
   {
-    search::HouseDetector houser(index);
+    search::HouseDetector houser(dataSource);
     StreetIDsByName toDo;
     toDo.streetNames.push_back("проспект Независимости");
     toDo.streetNames.push_back("Московская улица");
     toDo.streetNames.push_back("Вишнёвый переулок");
     toDo.streetNames.push_back("Студенческий переулок");
     toDo.streetNames.push_back("Полоцкий переулок");
-    index.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
+    dataSource.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
     houser.LoadStreets(toDo.GetFeatureIDs());
     TEST_GREATER_OR_EQUAL(houser.MergeStreets(), 1, ());
     TEST_LESS_OR_EQUAL(houser.MergeStreets(), 8, ());
   }
 
   {
-    search::HouseDetector houser(index);
+    search::HouseDetector houser(dataSource);
     StreetIDsByName toDo;
     toDo.streetNames.push_back("проспект Независимости");
     toDo.streetNames.push_back("Московская улица");
     toDo.streetNames.push_back("улица Кирова");
     toDo.streetNames.push_back("улица Городской Вал");
-    index.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
+    dataSource.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
     houser.LoadStreets(toDo.GetFeatureIDs());
     TEST_GREATER_OR_EQUAL(houser.MergeStreets(), 1, ());
     TEST_LESS_OR_EQUAL(houser.MergeStreets(), 10, ());
@@ -257,14 +257,14 @@ UNIT_TEST(HS_StreetsMerge)
 namespace
 {
 
-m2::PointD FindHouse(DataSourceBase & index, vector<string> const & streets,
+m2::PointD FindHouse(DataSourceBase & dataSource, vector<string> const & streets,
                      string const & houseName, double offset)
 {
-  search::HouseDetector houser(index);
+  search::HouseDetector houser(dataSource);
 
   StreetIDsByName toDo;
   toDo.streetNames = streets;
-  index.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
+  dataSource.ForEachInScale([&toDo](FeatureType & ft) { toDo(ft); }, scales::GetUpperScale());
 
   if (houser.LoadStreets(toDo.GetFeatureIDs()) > 0)
     TEST_GREATER(houser.MergeStreets(), 0, ());
@@ -284,29 +284,29 @@ UNIT_TEST(HS_FindHouseSmoke)
 {
   classificator::Load();
 
-  DataSource index;
-  auto const p = index.Register(LocalCountryFile::MakeForTesting("minsk-pass"));
+  DataSource dataSource;
+  auto const p = dataSource.Register(LocalCountryFile::MakeForTesting("minsk-pass"));
   TEST(p.first.IsAlive(), ());
   TEST_EQUAL(MwmSet::RegResult::Success, p.second, ());
 
   {
     vector<string> streetName(1, "Московская улица");
-    TEST_ALMOST_EQUAL_ULPS(FindHouse(index, streetName, "7", 100),
+    TEST_ALMOST_EQUAL_ULPS(FindHouse(dataSource, streetName, "7", 100),
                       m2::PointD(27.539850827603416406, 64.222406776416349317), ());
   }
   {
     vector<string> streetName(1, "проспект Независимости");
-    TEST_ALMOST_EQUAL_ULPS(FindHouse(index, streetName, "10", 40),
+    TEST_ALMOST_EQUAL_ULPS(FindHouse(dataSource, streetName, "10", 40),
                       m2::PointD(27.551428582902474318, 64.234707387050306693), ());
   }
   {
     vector<string> streetName(1, "улица Ленина");
 
     /// @todo This cases doesn't work, but should in new search algorithms.
-    //m2::PointD pt = FindHouse(index, streetName, "28", 50);
-    //m2::PointD pt = FindHouse(index, streetName, "30", 50);
+    //m2::PointD pt = FindHouse(dataSource, streetName, "28", 50);
+    //m2::PointD pt = FindHouse(dataSource, streetName, "30", 50);
 
-    m2::PointD pt = FindHouse(index, streetName, "21", 50);
+    m2::PointD pt = FindHouse(dataSource, streetName, "21", 50);
     TEST_ALMOST_EQUAL_ULPS(pt, m2::PointD(27.56477391395549148, 64.234502198059132638), ());
   }
 }
@@ -385,8 +385,8 @@ UNIT_TEST(HS_MWMSearch)
     return;
   }
 
-  DataSource index;
-  auto p = index.Register(LocalCountryFile::MakeForTesting(country));
+  DataSource dataSource;
+  auto p = dataSource.Register(LocalCountryFile::MakeForTesting(country));
   if (p.second != MwmSet::RegResult::Success)
   {
     LOG(LWARNING, ("MWM file not found"));
@@ -395,7 +395,7 @@ UNIT_TEST(HS_MWMSearch)
   TEST(p.first.IsAlive(), ());
 
   CollectStreetIDs streetIDs;
-  index.ForEachInScale(streetIDs, scales::GetUpperScale());
+  dataSource.ForEachInScale(streetIDs, scales::GetUpperScale());
   streetIDs.Finish();
 
   string line;
@@ -430,7 +430,7 @@ UNIT_TEST(HS_MWMSearch)
 
   sort(addresses.begin(), addresses.end());
 
-  search::HouseDetector detector(index);
+  search::HouseDetector detector(dataSource);
   size_t all = 0, matched = 0, notMatched = 0;
 
   size_t const percent = max(size_t(1), addresses.size() / 100);
diff --git a/search/search_tests/locality_finder_test.cpp b/search/search_tests/locality_finder_test.cpp
index 3ddbf96396..c187f87cd4 100644
--- a/search/search_tests/locality_finder_test.cpp
+++ b/search/search_tests/locality_finder_test.cpp
@@ -22,7 +22,7 @@ class LocalityFinderTest : public generator::tests_support::TestWithClassificato
 {
   platform::LocalCountryFile m_worldFile;
 
-  DataSource m_index;
+  DataSource m_dataSource;
 
   ::base::Cancellable m_cancellable;
   search::VillagesCache m_villagesCache;
@@ -34,14 +34,14 @@ class LocalityFinderTest : public generator::tests_support::TestWithClassificato
 public:
   LocalityFinderTest()
     : m_villagesCache(m_cancellable)
-    , m_boundariesTable(m_index)
-    , m_finder(m_index, m_boundariesTable, m_villagesCache)
+    , m_boundariesTable(m_dataSource)
+    , m_finder(m_dataSource, m_boundariesTable, m_villagesCache)
   {
     m_worldFile = platform::LocalCountryFile::MakeForTesting("World");
 
     try
     {
-      auto const p = m_index.Register(m_worldFile);
+      auto const p = m_dataSource.Register(m_worldFile);
       TEST_EQUAL(MwmSet::RegResult::Success, p.second, ());
 
       MwmSet::MwmId const & id = p.first;
diff --git a/search/search_tests_support/helpers.cpp b/search/search_tests_support/helpers.cpp
index d23a7ec9cd..3816f3650e 100644
--- a/search/search_tests_support/helpers.cpp
+++ b/search/search_tests_support/helpers.cpp
@@ -13,7 +13,7 @@ namespace search
 {
 SearchTest::SearchTest()
   : m_scopedLog(LDEBUG)
-  , m_engine(m_index, make_unique<storage::CountryInfoGetterForTesting>(), Engine::Params{})
+  , m_engine(m_dataSource, make_unique<storage::CountryInfoGetterForTesting>(), Engine::Params{})
 {
   SetViewport(MercatorBounds::FullRect());
 }
@@ -36,7 +36,7 @@ bool SearchTest::ResultsMatch(string const & query, string const & locale,
 {
   tests_support::TestSearchRequest request(m_engine, query, locale, Mode::Everywhere, m_viewport);
   request.Run();
-  return MatchResults(m_index, rules, request.Results());
+  return MatchResults(m_dataSource, rules, request.Results());
 }
 
 bool SearchTest::ResultsMatch(string const & query, Mode mode,
@@ -44,12 +44,12 @@ bool SearchTest::ResultsMatch(string const & query, Mode mode,
 {
   tests_support::TestSearchRequest request(m_engine, query, "en", mode, m_viewport);
   request.Run();
-  return MatchResults(m_index, rules, request.Results());
+  return MatchResults(m_dataSource, rules, request.Results());
 }
 
 bool SearchTest::ResultsMatch(vector<search::Result> const & results, TRules const & rules)
 {
-  return MatchResults(m_index, rules, results);
+  return MatchResults(m_dataSource, rules, results);
 }
 
 bool SearchTest::ResultsMatch(SearchParams const & params, TRules const & rules)
@@ -61,7 +61,7 @@ bool SearchTest::ResultsMatch(SearchParams const & params, TRules const & rules)
 
 bool SearchTest::ResultMatches(search::Result const & result, TRule const & rule)
 {
-  return tests_support::ResultMatches(m_index, rule, result);
+  return tests_support::ResultMatches(m_dataSource, rule, result);
 }
 
 unique_ptr<tests_support::TestSearchRequest> SearchTest::MakeRequest(
@@ -84,7 +84,7 @@ size_t SearchTest::CountFeatures(m2::RectD const & rect)
 {
   size_t count = 0;
   auto counter = [&count](const FeatureType & /* ft */) { ++count; };
-  m_index.ForEachInRect(counter, rect, scales::GetUpperScale());
+  m_dataSource.ForEachInRect(counter, rect, scales::GetUpperScale());
   return count;
 }
 
diff --git a/search/search_tests_support/test_results_matching.cpp b/search/search_tests_support/test_results_matching.cpp
index ede4170315..381f18f876 100644
--- a/search/search_tests_support/test_results_matching.cpp
+++ b/search/search_tests_support/test_results_matching.cpp
@@ -62,7 +62,7 @@ string AlternativesMatchingRule::ToString() const
   return os.str();
 }
 
-bool MatchResults(DataSourceBase const & index, vector<shared_ptr<MatchingRule>> rules,
+bool MatchResults(DataSourceBase const & dataSource, vector<shared_ptr<MatchingRule>> rules,
                   vector<search::Result> const & actual)
 {
   vector<FeatureID> resultIds;
@@ -83,7 +83,7 @@ bool MatchResults(DataSourceBase const & index, vector<shared_ptr<MatchingRule>>
     }
     unexpected.push_back(DebugPrint(feature) + " from " + DebugPrint(feature.GetID().m_mwmId));
   };
-  index.ReadFeatures(removeMatched, resultIds);
+  dataSource.ReadFeatures(removeMatched, resultIds);
 
   if (rules.empty() && unexpected.empty())
     return true;
@@ -100,18 +100,18 @@ bool MatchResults(DataSourceBase const & index, vector<shared_ptr<MatchingRule>>
   return false;
 }
 
-bool MatchResults(DataSourceBase const & index, vector<shared_ptr<MatchingRule>> rules,
+bool MatchResults(DataSourceBase const & dataSource, vector<shared_ptr<MatchingRule>> rules,
                   search::Results const & actual)
 {
   vector<search::Result> const results(actual.begin(), actual.end());
-  return MatchResults(index, rules, results);
+  return MatchResults(dataSource, rules, results);
 }
 
-bool ResultMatches(DataSourceBase const & index, shared_ptr<MatchingRule> rule,
+bool ResultMatches(DataSourceBase const & dataSource, shared_ptr<MatchingRule> rule,
                    search::Result const & result)
 {
   bool matches = false;
-  index.ReadFeature([&](FeatureType const & ft) { matches = rule->Matches(ft); }, result.GetFeatureID());
+  dataSource.ReadFeature([&](FeatureType const & ft) { matches = rule->Matches(ft); }, result.GetFeatureID());
   return matches;
 }
 
diff --git a/search/search_tests_support/test_results_matching.hpp b/search/search_tests_support/test_results_matching.hpp
index 5407976a69..f6d6fd72d5 100644
--- a/search/search_tests_support/test_results_matching.hpp
+++ b/search/search_tests_support/test_results_matching.hpp
@@ -74,11 +74,11 @@ std::shared_ptr<MatchingRule> AlternativesMatch(TArgs &&... args)
   return std::make_shared<AlternativesMatchingRule>(std::forward<TArgs>(args)...);
 }
 
-bool MatchResults(DataSourceBase const & index, std::vector<std::shared_ptr<MatchingRule>> rules,
+bool MatchResults(DataSourceBase const & dataSource, std::vector<std::shared_ptr<MatchingRule>> rules,
                   std::vector<search::Result> const & actual);
-bool MatchResults(DataSourceBase const & index, std::vector<std::shared_ptr<MatchingRule>> rules,
+bool MatchResults(DataSourceBase const & dataSource, std::vector<std::shared_ptr<MatchingRule>> rules,
                   search::Results const & actual);
-bool ResultMatches(DataSourceBase const & index, std::shared_ptr<MatchingRule> rule,
+bool ResultMatches(DataSourceBase const & dataSource, std::shared_ptr<MatchingRule> rule,
                    search::Result const & result);
 
 std::string DebugPrint(MatchingRule const & rule);
diff --git a/search/search_tests_support/test_search_engine.cpp b/search/search_tests_support/test_search_engine.cpp
index bd00d321ce..a9c8dffff2 100644
--- a/search/search_tests_support/test_search_engine.cpp
+++ b/search/search_tests_support/test_search_engine.cpp
@@ -12,15 +12,15 @@ namespace search
 {
 namespace tests_support
 {
-TestSearchEngine::TestSearchEngine(DataSourceBase & index, unique_ptr<storage::CountryInfoGetter> infoGetter,
+TestSearchEngine::TestSearchEngine(DataSourceBase & dataSource, unique_ptr<storage::CountryInfoGetter> infoGetter,
                                    Engine::Params const & params)
-  : m_infoGetter(move(infoGetter)), m_engine(index, GetDefaultCategories(), *m_infoGetter, params)
+  : m_infoGetter(move(infoGetter)), m_engine(dataSource, GetDefaultCategories(), *m_infoGetter, params)
 {
 }
 
-TestSearchEngine::TestSearchEngine(DataSourceBase & index, Engine::Params const & params)
+TestSearchEngine::TestSearchEngine(DataSourceBase & dataSource, Engine::Params const & params)
   : m_infoGetter(storage::CountryInfoReader::CreateCountryInfoReader(GetPlatform()))
-  , m_engine(index, GetDefaultCategories(), *m_infoGetter, params)
+  , m_engine(dataSource, GetDefaultCategories(), *m_infoGetter, params)
 {
 }
 
diff --git a/search/search_tests_support/test_search_engine.hpp b/search/search_tests_support/test_search_engine.hpp
index c73d85698e..bc51c33bac 100644
--- a/search/search_tests_support/test_search_engine.hpp
+++ b/search/search_tests_support/test_search_engine.hpp
@@ -18,9 +18,9 @@ namespace tests_support
 class TestSearchEngine
 {
 public:
-  TestSearchEngine(DataSourceBase & index, std::unique_ptr<storage::CountryInfoGetter> infoGetter,
+  TestSearchEngine(DataSourceBase & dataSource, std::unique_ptr<storage::CountryInfoGetter> infoGetter,
                    Engine::Params const & params);
-  TestSearchEngine(DataSourceBase & index, Engine::Params const & params);
+  TestSearchEngine(DataSourceBase & dataSource, Engine::Params const & params);
 
   void SetLocale(std::string const & locale) { m_engine.SetLocale(locale); }
 
diff --git a/search/search_tests_support/test_with_custom_mwms.hpp b/search/search_tests_support/test_with_custom_mwms.hpp
index ccbf30606b..606ea08b2e 100644
--- a/search/search_tests_support/test_with_custom_mwms.hpp
+++ b/search/search_tests_support/test_with_custom_mwms.hpp
@@ -23,7 +23,7 @@ class TestWithCustomMwms : public generator::tests_support::TestWithCustomMwms
 public:
   TestWithCustomMwms()
   {
-    editor::tests_support::SetUpEditorForTesting(my::make_unique<EditorDelegate>(m_index));
+    editor::tests_support::SetUpEditorForTesting(my::make_unique<EditorDelegate>(m_dataSource));
   }
 
   ~TestWithCustomMwms() override { editor::tests_support::TearDownEditorForTesting(); }
@@ -31,7 +31,7 @@ public:
   template <typename EditorFn>
   void EditFeature(FeatureID const & id, EditorFn && fn)
   {
-    EditableDataSource::FeaturesLoaderGuard loader(m_index, id.m_mwmId);
+    EditableDataSource::FeaturesLoaderGuard loader(m_dataSource, id.m_mwmId);
     FeatureType ft;
     CHECK(loader.GetFeatureByIndex(id.m_index, ft), ());
     editor::tests_support::EditFeature(ft, std::forward<EditorFn>(fn));
diff --git a/search/utils.cpp b/search/utils.cpp
index b8d6867a34..9dca350b72 100644
--- a/search/utils.cpp
+++ b/search/utils.cpp
@@ -42,24 +42,24 @@ strings::LevenshteinDFA BuildLevenshteinDFA(strings::UniString const & s)
   return strings::LevenshteinDFA(s, 1 /* prefixSize */, kAllowedMisprints, GetMaxErrorsForToken(s));
 }
 
-MwmSet::MwmHandle FindWorld(DataSourceBase const & index, vector<shared_ptr<MwmInfo>> const & infos)
+MwmSet::MwmHandle FindWorld(DataSourceBase const & dataSource, vector<shared_ptr<MwmInfo>> const & infos)
 {
   MwmSet::MwmHandle handle;
   for (auto const & info : infos)
   {
     if (info->GetType() == MwmInfo::WORLD)
     {
-      handle = index.GetMwmHandleById(MwmSet::MwmId(info));
+      handle = dataSource.GetMwmHandleById(MwmSet::MwmId(info));
       break;
     }
   }
   return handle;
 }
 
-MwmSet::MwmHandle FindWorld(DataSourceBase const & index)
+MwmSet::MwmHandle FindWorld(DataSourceBase const & dataSource)
 {
   vector<shared_ptr<MwmInfo>> infos;
-  index.GetMwmsInfo(infos);
-  return FindWorld(index, infos);
+  dataSource.GetMwmsInfo(infos);
+  return FindWorld(dataSource, infos);
 }
 }  // namespace search
diff --git a/search/utils.hpp b/search/utils.hpp
index 70fd5e4e8c..c36ef22f8d 100644
--- a/search/utils.hpp
+++ b/search/utils.hpp
@@ -114,7 +114,7 @@ bool FillCategories(QuerySliceOnRawStrings<T> const & slice, Locales const & loc
   return !types.empty();
 }
 
-MwmSet::MwmHandle FindWorld(DataSourceBase const &index,
+MwmSet::MwmHandle FindWorld(DataSourceBase const & dataSource,
                             std::vector<std::shared_ptr<MwmInfo>> const &infos);
-MwmSet::MwmHandle FindWorld(DataSourceBase const & index);
+MwmSet::MwmHandle FindWorld(DataSourceBase const & dataSource);
 }  // namespace search
diff --git a/track_analyzing/track_matcher.cpp b/track_analyzing/track_matcher.cpp
index f9d708504b..dffa3c2fcb 100644
--- a/track_analyzing/track_matcher.cpp
+++ b/track_analyzing/track_matcher.cpp
@@ -59,14 +59,14 @@ TrackMatcher::TrackMatcher(storage::Storage const & storage, NumMwmId mwmId,
 {
   auto localCountryFile = storage.GetLatestLocalFile(countryFile);
   CHECK(localCountryFile, ("Can't find latest country file for", countryFile.GetName()));
-  auto registerResult = m_index.Register(*localCountryFile);
+  auto registerResult = m_dataSource.Register(*localCountryFile);
   CHECK_EQUAL(registerResult.second, MwmSet::RegResult::Success,
               ("Can't register mwm", countryFile.GetName()));
 
-  MwmSet::MwmHandle const handle = m_index.GetMwmHandleByCountryFile(countryFile);
+  MwmSet::MwmHandle const handle = m_dataSource.GetMwmHandleByCountryFile(countryFile);
   m_graph = make_unique<IndexGraph>(
       make_shared<Geometry>(
-          GeometryLoader::Create(m_index, handle, m_vehicleModel, false /* loadAltitudes */)),
+          GeometryLoader::Create(m_dataSource, handle, m_vehicleModel, false /* loadAltitudes */)),
       EdgeEstimator::Create(VehicleType::Car, *m_vehicleModel, nullptr /* trafficStash */));
 
   DeserializeIndexGraph(*handle.GetValue<MwmValue>(), VehicleType::Car, *m_graph);
@@ -85,7 +85,7 @@ void TrackMatcher::MatchTrack(vector<DataPoint> const & track, vector<MatchedTra
   {
     for (; trackBegin < steps.size(); ++trackBegin)
     {
-      steps[trackBegin].FillCandidatesWithNearbySegments(m_index, *m_graph, *m_vehicleModel,
+      steps[trackBegin].FillCandidatesWithNearbySegments(m_dataSource, *m_graph, *m_vehicleModel,
                                                          m_mwmId);
       if (steps[trackBegin].HasCandidates())
         break;
@@ -132,10 +132,10 @@ TrackMatcher::Step::Step(DataPoint const & dataPoint)
 }
 
 void TrackMatcher::Step::FillCandidatesWithNearbySegments(
-    DataSourceBase const & index, IndexGraph const & graph, VehicleModelInterface const & vehicleModel,
+    DataSourceBase const & dataSource, IndexGraph const & graph, VehicleModelInterface const & vehicleModel,
     NumMwmId mwmId)
 {
-  index.ForEachInRect(
+  dataSource.ForEachInRect(
       [&](FeatureType const & ft) {
         if (!ft.GetID().IsValid())
           return;
diff --git a/track_analyzing/track_matcher.hpp b/track_analyzing/track_matcher.hpp
index 9a3b1b4eba..de386bb765 100644
--- a/track_analyzing/track_matcher.hpp
+++ b/track_analyzing/track_matcher.hpp
@@ -57,7 +57,7 @@ private:
     DataPoint const & GetDataPoint() const { return m_dataPoint; }
     routing::Segment const & GetSegment() const { return m_segment; }
     bool HasCandidates() const { return !m_candidates.empty(); }
-    void FillCandidatesWithNearbySegments(DataSourceBase const & index, routing::IndexGraph const & graph,
+    void FillCandidatesWithNearbySegments(DataSourceBase const & dataSource, routing::IndexGraph const & graph,
                                           routing::VehicleModelInterface const & vehicleModel,
                                           routing::NumMwmId mwmId);
     void FillCandidates(Step const & previousStep, routing::IndexGraph & graph);
@@ -75,7 +75,7 @@ private:
   };
 
   routing::NumMwmId const m_mwmId;
-  DataSource m_index;
+  DataSource m_dataSource;
   std::shared_ptr<routing::VehicleModelInterface> m_vehicleModel;
   std::unique_ptr<routing::IndexGraph> m_graph;
   uint64_t m_tracksCount = 0;
diff --git a/ugc/api.cpp b/ugc/api.cpp
index 6125d57065..0ee32a2881 100644
--- a/ugc/api.cpp
+++ b/ugc/api.cpp
@@ -9,8 +9,8 @@ using namespace ugc;
 
 namespace ugc
 {
-Api::Api(DataSourceBase const & index, NumberOfUnsynchronizedCallback const & callback)
-  : m_storage(index), m_loader(index)
+Api::Api(DataSourceBase const & dataSource, NumberOfUnsynchronizedCallback const & callback)
+  : m_storage(dataSource), m_loader(dataSource)
 {
   m_thread.Push([this, callback] {
     m_storage.Load();
diff --git a/ugc/api.hpp b/ugc/api.hpp
index 7e28295226..40198c076c 100644
--- a/ugc/api.hpp
+++ b/ugc/api.hpp
@@ -24,7 +24,7 @@ public:
   using OnResultCallback = platform::SafeCallback<void(Storage::SettingResult const result)>;
   using NumberOfUnsynchronizedCallback = std::function<void(size_t number)>;
 
-  Api(DataSourceBase const & index, NumberOfUnsynchronizedCallback const & callback);
+  Api(DataSourceBase const & dataSource, NumberOfUnsynchronizedCallback const & callback);
 
   void GetUGC(FeatureID const & id, UGCCallbackUnsafe const & callback);
   void SetUGCUpdate(FeatureID const & id, UGCUpdate const & ugc,
diff --git a/ugc/loader.cpp b/ugc/loader.cpp
index b6a4fc2c4a..3c2ad20085 100644
--- a/ugc/loader.cpp
+++ b/ugc/loader.cpp
@@ -7,11 +7,11 @@
 
 namespace ugc
 {
-Loader::Loader(DataSourceBase const & index) : m_index(index) {}
+Loader::Loader(DataSourceBase const & dataSource) : m_dataSource(dataSource) {}
 
 UGC Loader::GetUGC(FeatureID const & featureId)
 {
-  auto const handle = m_index.GetMwmHandleById(featureId.m_mwmId);
+  auto const handle = m_dataSource.GetMwmHandleById(featureId.m_mwmId);
 
   if (!handle.IsAlive())
     return {};
diff --git a/ugc/loader.hpp b/ugc/loader.hpp
index 6af167f0a6..8a5fa3b65b 100644
--- a/ugc/loader.hpp
+++ b/ugc/loader.hpp
@@ -18,7 +18,7 @@ namespace ugc
 class Loader
 {
 public:
-  Loader(DataSourceBase const & index);
+  Loader(DataSourceBase const & dataSource);
   UGC GetUGC(FeatureID const & featureId);
 
 private:
@@ -30,7 +30,7 @@ private:
 
   using EntryPtr = std::shared_ptr<Entry>;
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   std::map<MwmSet::MwmId, EntryPtr> m_deserializers;
   std::mutex m_mutex;
 };
diff --git a/ugc/storage.cpp b/ugc/storage.cpp
index 927f34e85a..9909b145c5 100644
--- a/ugc/storage.cpp
+++ b/ugc/storage.cpp
@@ -443,7 +443,7 @@ uint64_t Storage::UGCSizeAtIndex(size_t const indexPosition) const
 unique_ptr<FeatureType> Storage::GetFeature(FeatureID const & id) const
 {
   CHECK(id.IsValid(), ());
-  EditableDataSource::FeaturesLoaderGuard guard(m_index, id.m_mwmId);
+  EditableDataSource::FeaturesLoaderGuard guard(m_dataSource, id.m_mwmId);
   auto feature = guard.GetOriginalOrEditedFeatureByIndex(id.m_index);
   feature->ParseGeometry(FeatureType::BEST_GEOMETRY);
   if (feature->GetFeatureType() == feature::EGeomType::GEOM_AREA)
diff --git a/ugc/storage.hpp b/ugc/storage.hpp
index 9f1b2c337d..bc14492eed 100644
--- a/ugc/storage.hpp
+++ b/ugc/storage.hpp
@@ -16,7 +16,7 @@ namespace ugc
 class Storage
 {
 public:
-  explicit Storage(DataSourceBase const & index) : m_index(index) {}
+  explicit Storage(DataSourceBase const & dataSource) : m_dataSource(dataSource) {}
 
   UGCUpdate GetUGCUpdate(FeatureID const & id) const;
 
@@ -46,7 +46,7 @@ private:
   std::unique_ptr<FeatureType> GetFeature(FeatureID const & id) const;
   void Migrate(std::string const & indexFilePath);
 
-  DataSourceBase const & m_index;
+  DataSourceBase const & m_dataSource;
   UpdateIndexes m_indexes;
   size_t m_numberOfDeleted = 0;
 };
diff --git a/ugc/ugc_tests/storage_tests.cpp b/ugc/ugc_tests/storage_tests.cpp
index 13ac9a384a..da2815e5ae 100644
--- a/ugc/ugc_tests/storage_tests.cpp
+++ b/ugc/ugc_tests/storage_tests.cpp
@@ -102,7 +102,7 @@ public:
     return FeatureIdForPoint(mercator, ftypes::IsRailwayStationChecker::Instance());
   }
 
-  DataSourceBase & GetIndex() { return m_index; }
+  DataSourceBase & GetDataSource() { return m_dataSource; }
 
   ~MwmBuilder()
   {
@@ -129,7 +129,7 @@ private:
       fn(builder);
     }
 
-    auto result = m_index.RegisterMap(m_testMwm);
+    auto result = m_dataSource.RegisterMap(m_testMwm);
     CHECK_EQUAL(result.second, MwmSet::RegResult::Success, ());
 
     auto const & id = result.first;
@@ -152,19 +152,19 @@ private:
       if (checker(featureType))
         id = featureType.GetID();
     };
-    m_index.ForEachInRect(fn, rect, scales::GetUpperScale());
+    m_dataSource.ForEachInRect(fn, rect, scales::GetUpperScale());
     CHECK(id.IsValid(), ());
     return id;
   }
 
   void Cleanup(platform::LocalCountryFile const & map)
   {
-    m_index.DeregisterMap(map.GetCountryFile());
+    m_dataSource.DeregisterMap(map.GetCountryFile());
     platform::CountryIndexes::DeleteFromDisk(map);
     map.DeleteFromDisk(MapOptions::Map);
   }
 
-  DataSource m_index;
+  DataSource m_dataSource;
   storage::CountryInfoGetterForTesting m_infoGetter;
   platform::LocalCountryFile m_testMwm;
 };
@@ -188,7 +188,7 @@ UNIT_CLASS_TEST(StorageTest, Smoke)
   builder.Build({TestCafe(point)});
   auto const id = builder.FeatureIdForCafeAtPoint(point);
   auto const original = MakeTestUGCUpdate(Time(chrono::hours(24 * 300)));
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
   TEST_EQUAL(storage.SetUGCUpdate(id, original), Storage::SettingResult::Success, ());
   auto const actual = storage.GetUGCUpdate(id);
@@ -210,7 +210,7 @@ UNIT_CLASS_TEST(StorageTest, DuplicatesAndDefragmentationSmoke)
   auto const second = MakeTestUGCUpdate(Time(chrono::hours(24 * 100)));
   auto const third = MakeTestUGCUpdate(Time(chrono::hours(24 * 300)));
   auto const last = MakeTestUGCUpdate(Time(chrono::hours(24 * 100)));
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
   TEST_EQUAL(storage.SetUGCUpdate(cafeId, first), Storage::SettingResult::Success, ());
   TEST_EQUAL(storage.SetUGCUpdate(cafeId, second), Storage::SettingResult::Success, ());
@@ -236,7 +236,7 @@ UNIT_CLASS_TEST(StorageTest, DifferentTypes)
   auto const railwayId = builder.FeatureIdForRailwayAtPoint(point);
   auto const cafeUGC = MakeTestUGCUpdate(Time(chrono::hours(24 * 10)));
   auto const railwayUGC = MakeTestUGCUpdate(Time(chrono::hours(24 * 300)));
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
   TEST_EQUAL(storage.SetUGCUpdate(cafeId, cafeUGC), Storage::SettingResult::Success, ());
   TEST_EQUAL(storage.SetUGCUpdate(railwayId, railwayUGC), Storage::SettingResult::Success, ());
@@ -256,14 +256,14 @@ UNIT_CLASS_TEST(StorageTest, LoadIndex)
   auto const railwayUGC = MakeTestUGCUpdate(Time(chrono::hours(24 * 300)));
 
   {
-    Storage storage(builder.GetIndex());
+    Storage storage(builder.GetDataSource());
     storage.Load();
     TEST_EQUAL(storage.SetUGCUpdate(cafeId, cafeUGC), Storage::SettingResult::Success, ());
     TEST_EQUAL(storage.SetUGCUpdate(railwayId, railwayUGC), Storage::SettingResult::Success, ());
     storage.SaveIndex();
   }
 
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
   auto const & indexArray = storage.GetIndexesForTesting();
   TEST_EQUAL(indexArray.size(), 2, ());
@@ -286,7 +286,7 @@ UNIT_CLASS_TEST(StorageTest, ContentTest)
   auto const cafeId = builder.FeatureIdForCafeAtPoint(cafePoint);
   auto const oldUGC = MakeTestUGCUpdate(Time(chrono::hours(24 * 10)));
   auto const newUGC = MakeTestUGCUpdate(Time(chrono::hours(24 * 300)));
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
   TEST_EQUAL(storage.SetUGCUpdate(cafeId, oldUGC), Storage::SettingResult::Success, ());
   TEST_EQUAL(storage.SetUGCUpdate(cafeId, newUGC), Storage::SettingResult::Success, ());
@@ -338,7 +338,7 @@ UNIT_CLASS_TEST(StorageTest, InvalidUGC)
   m2::PointD const cafePoint(1.0, 1.0);
   builder.Build({TestCafe(cafePoint)});
   auto const cafeId = builder.FeatureIdForCafeAtPoint(cafePoint);
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
 
   UGCUpdate first;
@@ -364,7 +364,7 @@ UNIT_CLASS_TEST(StorageTest, DifferentUGCVersions)
   m2::PointD const secondPoint(2.0, 2.0);
   builder.Build({TestCafe(firstPoint), TestCafe(secondPoint)});
 
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
 
   auto const firstId = builder.FeatureIdForCafeAtPoint(firstPoint);
@@ -389,13 +389,13 @@ UNIT_CLASS_TEST(StorageTest, NumberOfUnsynchronized)
   auto const cafeUGC = MakeTestUGCUpdate(Time(chrono::hours(24 * 10)));
 
   {
-    Storage storage(builder.GetIndex());
+    Storage storage(builder.GetDataSource());
     storage.Load();
     TEST_EQUAL(storage.SetUGCUpdate(cafeId, cafeUGC), Storage::SettingResult::Success, ());
     storage.SaveIndex();
   }
 
-  Storage storage(builder.GetIndex());
+  Storage storage(builder.GetDataSource());
   storage.Load();
   TEST_EQUAL(storage.GetNumberOfUnsynchronized(), 1, ());
 
@@ -419,7 +419,7 @@ UNIT_CLASS_TEST(StorageTest, GetNumberOfUnsentSeparately)
   auto const cafeUGC = MakeTestUGCUpdate(Time(chrono::hours(24 * 10)));
 
   {
-    Storage storage(builder.GetIndex());
+    Storage storage(builder.GetDataSource());
     storage.Load();
     TEST_EQUAL(storage.SetUGCUpdate(cafeId, cafeUGC), Storage::SettingResult::Success, ());
     storage.SaveIndex();
@@ -429,7 +429,7 @@ UNIT_CLASS_TEST(StorageTest, GetNumberOfUnsentSeparately)
   TEST_EQUAL(lightweight::GetNumberOfUnsentUGC(), 1, ());
 
   {
-    Storage storage(builder.GetIndex());
+    Storage storage(builder.GetDataSource());
     storage.Load();
     storage.MarkAllAsSynchronized();
     TEST_EQUAL(storage.GetNumberOfUnsynchronized(), 0, ());
@@ -463,7 +463,7 @@ UNIT_TEST(UGC_IndexMigrationFromV0ToV1Smoke)
   builder.Build({});
 
   auto const v0IndexFilePath = indexFilePath + "." + version;
-  Storage s(builder.GetIndex());
+  Storage s(builder.GetDataSource());
   s.LoadForTesting(indexFilePath);
   uint64_t migratedIndexFileSize = 0;
   uint64_t v0IndexFileSize = 0;
diff --git a/xcode/indexer/indexer.xcodeproj/project.pbxproj b/xcode/indexer/indexer.xcodeproj/project.pbxproj
index db941cbd7b..6208abc9b5 100644
--- a/xcode/indexer/indexer.xcodeproj/project.pbxproj
+++ b/xcode/indexer/indexer.xcodeproj/project.pbxproj
@@ -99,7 +99,7 @@
 		670BAA971D0B06E1000302DA /* checker_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C60FC1AB065B100C38A8C /* checker_test.cpp */; };
 		670BAA981D0B06E1000302DA /* features_offsets_table_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C60FD1AB065B100C38A8C /* features_offsets_table_test.cpp */; };
 		670BAA9B1D0B06E1000302DA /* index_builder_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C61001AB065B100C38A8C /* index_builder_test.cpp */; };
-		670BAA9C1D0B06E1000302DA /* index_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C61011AB065B100C38A8C /* index_test.cpp */; };
+		670BAA9C1D0B06E1000302DA /* data_source_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C61011AB065B100C38A8C /* data_source_test.cpp */; };
 		670BAA9D1D0B06E1000302DA /* interval_index_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C61021AB065B100C38A8C /* interval_index_test.cpp */; };
 		670BAA9E1D0B06E1000302DA /* mwm_set_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C61041AB065B100C38A8C /* mwm_set_test.cpp */; };
 		670BAAA01D0B06E1000302DA /* scales_test.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 670C61061AB065B100C38A8C /* scales_test.cpp */; };
@@ -336,7 +336,7 @@
 		670C60FC1AB065B100C38A8C /* checker_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = checker_test.cpp; sourceTree = "<group>"; };
 		670C60FD1AB065B100C38A8C /* features_offsets_table_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = features_offsets_table_test.cpp; sourceTree = "<group>"; };
 		670C61001AB065B100C38A8C /* index_builder_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = index_builder_test.cpp; sourceTree = "<group>"; };
-		670C61011AB065B100C38A8C /* index_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = index_test.cpp; sourceTree = "<group>"; };
+		670C61011AB065B100C38A8C /* data_source_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = data_source_test.cpp; sourceTree = "<group>"; };
 		670C61021AB065B100C38A8C /* interval_index_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = interval_index_test.cpp; sourceTree = "<group>"; };
 		670C61041AB065B100C38A8C /* mwm_set_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = mwm_set_test.cpp; sourceTree = "<group>"; };
 		670C61061AB065B100C38A8C /* scales_test.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = scales_test.cpp; sourceTree = "<group>"; };
@@ -569,7 +569,7 @@
 				670C60FD1AB065B100C38A8C /* features_offsets_table_test.cpp */,
 				3D489BA81D3D1F8A0052AA38 /* features_vector_test.cpp */,
 				670C61001AB065B100C38A8C /* index_builder_test.cpp */,
-				670C61011AB065B100C38A8C /* index_test.cpp */,
+				670C61011AB065B100C38A8C /* data_source_test.cpp */,
 				670C61021AB065B100C38A8C /* interval_index_test.cpp */,
 				40A1C309202B321000F71672 /* locality_index_test.cpp */,
 				670C61041AB065B100C38A8C /* mwm_set_test.cpp */,
@@ -968,7 +968,7 @@
 				670BAA911D0B06B4000302DA /* categories_test.cpp in Sources */,
 				3D489BC81D3D22190052AA38 /* string_slice_tests.cpp in Sources */,
 				670BAAA11D0B06E1000302DA /* sort_and_merge_intervals_test.cpp in Sources */,
-				670BAA9C1D0B06E1000302DA /* index_test.cpp in Sources */,
+				670BAA9C1D0B06E1000302DA /* data_source_test.cpp in Sources */,
 				670BAA9B1D0B06E1000302DA /* index_builder_test.cpp in Sources */,
 				670C612C1AB0663400C38A8C /* testingmain.cpp in Sources */,
 				3D489BC61D3D220F0052AA38 /* editable_map_object_test.cpp in Sources */,