implementation without public API changes for alter index

Author: jepett0

ydb/core/kqp/provider/yql_kikimr_exec.cpp

@@ -1515,16 +1515,16 @@ class TKiSinkCallableExecutionTransformer : public TAsyncCallbackTransformer<TKi
                     }
                 } else if (name == "alterIndex") {
                     auto listNode = action.Value().Cast<TCoNameValueTupleList>();
-                    auto* alterIndex = alterTableRequest.add_alter_indexes();
                     for (const auto& indexSetting : listNode) {
                         auto name = indexSetting.Name().Value();
                         if (name == "indexName") {
-                            alterIndex->set_name(indexSetting.Value().Cast<TCoAtom>().StringValue());
+                            auto index = indexSetting.Value().Cast<TCoAtom>().StringValue();
+                            alterTableRequest.set_path(TStringBuilder() << alterTableRequest.path() << '/' << index << '/' << "indexImplTable");
                         } else if (name == "tableSettings") {
                             auto tableSettings = indexSetting.Value().Cast<TCoNameValueTupleList>();
                             for (const auto& tableSetting : tableSettings) {
-                                if (!ParsePartitioningSettings([&alterIndex]() {
-                                        return alterIndex->mutable_partitioning_settings();
+                                if (!ParsePartitioningSettings([&alterTableRequest]() {
+                                        return alterTableRequest.mutable_alter_partitioning_settings();
                                     }, tableSetting, ctx, true)
                                 ) {
                                     return SyncError();