Fix pg_tables when not using /Root database (#6032)

Author: qrort

ydb/core/kqp/provider/yql_kikimr_opt.cpp

@@ -60,7 +60,7 @@ TAutoPtr<IGraphTransformer> CreateKiLogicalOptProposalTransformer(TIntrusivePtr<
             if (auto maybeDatasink = node.Maybe<TCoCommit>().DataSink().Maybe<TKiDataSink>()) {
                 auto cluster = TString(maybeDatasink.Cast().Cluster());
 
-                ret = KiBuildQuery(node, ctx, sessionCtx->TablesPtr(), types, sessionCtx->Query().ConcurrentResults);
+                ret = KiBuildQuery(node, ctx, sessionCtx->GetDatabase(), sessionCtx->TablesPtr(), types, sessionCtx->Query().ConcurrentResults);
 
                 if (ret != inputNode) {
                     return ret;

ydb/core/kqp/provider/yql_kikimr_opt_build.cpp

@@ -844,7 +844,7 @@ TVector<TKiDataQueryBlock> MakeKiDataQueryBlocks(TExprBase node, const TKiExplor
 
 } // namespace
 
-TExprNode::TPtr KiBuildQuery(TExprBase node, TExprContext& ctx, TIntrusivePtr<TKikimrTablesData> tablesData,
+TExprNode::TPtr KiBuildQuery(TExprBase node, TExprContext& ctx, TStringBuf database, TIntrusivePtr<TKikimrTablesData> tablesData,
     TTypeAnnotationContext& types, bool concurrentResults) {
     if (!node.Maybe<TCoCommit>().DataSink().Maybe<TKiDataSink>()) {
         return node.Ptr();
@@ -858,14 +858,14 @@ TExprNode::TPtr KiBuildQuery(TExprBase node, TExprContext& ctx, TIntrusivePtr<TK
     VisitExpr(node.Ptr(), [&replaces](const TExprNode::TPtr& input) -> bool {
         if (input->IsCallable("PgTableContent")) {
             TPgTableContent content(input);
-            if (content.Table() == "pg_tables") {
+            if (content.Table().StringValue() == "pg_tables") {
                 replaces[input.Get()] = nullptr;
             }
         }
         return true;
     });
     if (!replaces.empty()) {
-        TExprNode::TPtr path = ctx.NewCallable(node.Pos(), "String", { ctx.NewAtom(node.Pos(), "/Root/.sys/pg_tables") });
+        TExprNode::TPtr path = ctx.NewCallable(node.Pos(), "String", { ctx.NewAtom(node.Pos(), TStringBuilder() << "/" << database << "/.sys/pg_tables") });
         auto table = ctx.NewList(node.Pos(), {ctx.NewAtom(node.Pos(), "table"), path});
         auto newKey = ctx.NewCallable(node.Pos(), "Key", {table});
 

ydb/core/kqp/provider/yql_kikimr_provider_impl.h

@@ -249,7 +249,7 @@ void FillLiteralProto(const NNodes::TCoDataCtor& literal, Ydb::TypedValue& proto
 void FillLiteralProto(const NNodes::TCoDataCtor& literal, NKqpProto::TKqpPhyLiteralValue& proto);
 
 // Optimizer rules
-TExprNode::TPtr KiBuildQuery(NNodes::TExprBase node, TExprContext& ctx, TIntrusivePtr<TKikimrTablesData> tablesData,
+TExprNode::TPtr KiBuildQuery(NNodes::TExprBase node, TExprContext& ctx, TStringBuf database, TIntrusivePtr<TKikimrTablesData> tablesData,
     TTypeAnnotationContext& types, bool sequentialResults);
 TExprNode::TPtr KiBuildResult(NNodes::TExprBase node,  const TString& cluster, TExprContext& ctx);