Added pragma to disallow fusing of joins (#32287)

Co-authored-by: Velikhov Pavel <[email protected]>

3 files changed, 3 insertions, 1 deletions

diff --git a/ydb/core/kqp/opt/physical/kqp_opt_phy.cpp b/ydb/core/kqp/opt/physical/kqp_opt_phy.cpp
index c588b2945be..e7e621b15ff 100644
--- a/ydb/core/kqp/opt/physical/kqp_opt_phy.cpp
+++ b/ydb/core/kqp/opt/physical/kqp_opt_phy.cpp
@@ -561,7 +561,7 @@ protected:
     {
         // TODO: Allow push to left stage for data queries.
         // It is now possible as we don't use datashard transactions for reads in data queries.
-        bool pushLeftStage = AllowFuseJoinInputs(node);
+        bool pushLeftStage = AllowFuseJoinInputs(node) && !KqpCtx.Config->OptDisallowFuseJoins.Get().GetOrElse(false);
         bool shuffleEliminationWithMap = KqpCtx.Config->OptShuffleEliminationWithMap.Get().GetOrElse(true);
         bool rightCollectStage = !KqpCtx.Config->GetAllowMultiBroadcasts();
         TExprBase output = DqBuildJoin(node, ctx, optCtx, *getParents(), IsGlobal,
diff --git a/ydb/core/kqp/provider/yql_kikimr_settings.cpp b/ydb/core/kqp/provider/yql_kikimr_settings.cpp
index 453905db99d..9ad10b6f3b8 100644
--- a/ydb/core/kqp/provider/yql_kikimr_settings.cpp
+++ b/ydb/core/kqp/provider/yql_kikimr_settings.cpp
@@ -91,6 +91,7 @@ TKikimrConfiguration::TKikimrConfiguration() {
     REGISTER_SETTING(*this, OptShuffleElimination);
     REGISTER_SETTING(*this, OptShuffleEliminationWithMap);
     REGISTER_SETTING(*this, OptShuffleEliminationForAggregation);
+    REGISTER_SETTING(*this, OptDisallowFuseJoins);
     REGISTER_SETTING(*this, OverridePlanner);
     REGISTER_SETTING(*this, UseGraceJoinCoreForMap);
     REGISTER_SETTING(*this, UseBlockHashJoin);
diff --git a/ydb/core/kqp/provider/yql_kikimr_settings.h b/ydb/core/kqp/provider/yql_kikimr_settings.h
index e79ac45ebf2..d2db480937a 100644
--- a/ydb/core/kqp/provider/yql_kikimr_settings.h
+++ b/ydb/core/kqp/provider/yql_kikimr_settings.h
@@ -84,6 +84,7 @@ public:
     NCommon::TConfSetting<bool, Static> OptShuffleEliminationWithMap;
     NCommon::TConfSetting<bool, Static> OptShuffleEliminationForAggregation;
     NCommon::TConfSetting<ui32, Static> CostBasedOptimizationLevel;
+    NCommon::TConfSetting<bool, Static> OptDisallowFuseJoins;
 
     // Use CostBasedOptimizationLevel for internal usage. This is a dummy flag that is mapped to the optimization level during parsing.
     NCommon::TConfSetting<TString, Static> CostBasedOptimization;