Revert some restriction on secondary index creation (#7963)

Author: MBkkt

ydb/core/base/table_index.cpp

@@ -105,9 +105,8 @@ bool IsCompatibleIndex(NKikimrSchemeOp::EIndexType indexType, const TTableColumn
             explain = "should be at least single index key column";
             return false;
         }
-        if (index.KeyColumns.size() <= table.Keys.size() &&
-            std::equal(index.KeyColumns.begin(), index.KeyColumns.end(), table.Keys.begin())) {
-            explain = "index keys are prefix of table keys";
+        if (index.KeyColumns == table.Keys) {
+            explain = "index keys shouldn't be table keys";
             return false;
         }
     } else {

ydb/core/base/ut/table_index_ut.cpp

@@ -15,32 +15,35 @@ Y_UNIT_TEST_SUITE (TableIndex) {
         auto type = NKikimrSchemeOp::EIndexType::EIndexTypeGlobal;
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"DATA1"}, {}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"DATA1", "DATA2"}, {}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"PK1", "PK2"}, {}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"DATA1"}, {"DATA3"}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
         {
             const TTableColumns Table2{{"PK", "DATA", NTableVectorKmeansTreeIndex::PostingTable_ParentIdColumn}, {"PK"}};
 
             UNIT_ASSERT(IsCompatibleIndex(type, Table2, {{NTableVectorKmeansTreeIndex::PostingTable_ParentIdColumn}, {}}, explain));
-            UNIT_ASSERT(explain.empty());
+            UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
             UNIT_ASSERT(IsCompatibleIndex(type, Table2, {{"DATA"}, {NTableVectorKmeansTreeIndex::PostingTable_ParentIdColumn}}, explain));
-            UNIT_ASSERT(explain.empty());
+            UNIT_ASSERT_STRINGS_EQUAL(explain, "");
         }
         {
             const TTableColumns Table3{{"PK", "DATA", NTableVectorKmeansTreeIndex::PostingTable_ParentIdColumn}, {NTableVectorKmeansTreeIndex::PostingTable_ParentIdColumn}};
 
             UNIT_ASSERT(IsCompatibleIndex(type, Table3, {{"DATA"}, {}}, explain));
-            UNIT_ASSERT(explain.empty());
+            UNIT_ASSERT_STRINGS_EQUAL(explain, "");
         }
+
+        UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"PK2"}, {}}, explain));
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
     }
 
     Y_UNIT_TEST (NotCompatibleSecondaryIndex) {
@@ -71,25 +74,25 @@ Y_UNIT_TEST_SUITE (TableIndex) {
         UNIT_ASSERT(!IsCompatibleIndex(type, Table, {{}, {}}, explain));
         UNIT_ASSERT_STRINGS_EQUAL(explain, "should be at least single index key column");
 
-        UNIT_ASSERT(!IsCompatibleIndex(type, Table, {{"PK2"}, {}}, explain));
-        UNIT_ASSERT_STRINGS_EQUAL(explain, "index keys are prefix of table keys");
+        UNIT_ASSERT(!IsCompatibleIndex(type, Table, {{"PK2", "PK1"}, {}}, explain));
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "index keys shouldn't be table keys");
     }
 
     Y_UNIT_TEST (CompatibleVectorIndex) {
         TString explain;
         auto type = NKikimrSchemeOp::EIndexType::EIndexTypeGlobalVectorKmeansTree;
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"DATA1"}, {}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"DATA1"}, {"DATA3"}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"PK1"}, {}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
 
         UNIT_ASSERT(IsCompatibleIndex(type, Table, {{"DATA1"}, {"DATA1"}}, explain));
-        UNIT_ASSERT(explain.empty());
+        UNIT_ASSERT_STRINGS_EQUAL(explain, "");
     }
 
     Y_UNIT_TEST (NotCompatibleVectorIndex) {