Add check for non-empty Handlers in AggregateCombine

Add check for input handlers in AggregateCombine.

2 files changed, 20 insertions, 1 deletions

diff --git a/ydb/core/kqp/opt/physical/kqp_opt_phy_olap_agg.cpp b/ydb/core/kqp/opt/physical/kqp_opt_phy_olap_agg.cpp
index 472930a7f8..7d8af7cc70 100644
--- a/ydb/core/kqp/opt/physical/kqp_opt_phy_olap_agg.cpp
+++ b/ydb/core/kqp/opt/physical/kqp_opt_phy_olap_agg.cpp
@@ -61,6 +61,10 @@ TExprBase KqpPushOlapAggregate(TExprBase node, TExprContext& ctx, const TKqpOpti
     }
 
     auto aggCombine = node.Cast<TCoAggregateCombine>();
+    if (aggCombine.Handlers().Size() == 0) {
+        return node;
+    }
+
     auto maybeRead = aggCombine.Input().Maybe<TKqpReadOlapTableRanges>();
     if (!maybeRead) {
         maybeRead = aggCombine.Input().Maybe<TCoExtractMembers>().Input().Maybe<TKqpReadOlapTableRanges>();
@@ -71,7 +75,6 @@ TExprBase KqpPushOlapAggregate(TExprBase node, TExprContext& ctx, const TKqpOpti
     }
 
     auto read = maybeRead.Cast();
-
     auto aggs = Build<TKqpOlapAggOperationList>(ctx, node.Pos());
     // TODO: TMaybeNode<TKqpOlapAggOperation>;
     for (auto handler: aggCombine.Handlers()) {
diff --git a/ydb/core/kqp/ut/kqp_olap_ut.cpp b/ydb/core/kqp/ut/kqp_olap_ut.cpp
index 765a7cf107..408f1fad59 100644
--- a/ydb/core/kqp/ut/kqp_olap_ut.cpp
+++ b/ydb/core/kqp/ut/kqp_olap_ut.cpp
@@ -1652,6 +1652,22 @@ Y_UNIT_TEST_SUITE(KqpOlap) {
         TestAggregationsInternal(cases);
     }
 
+    Y_UNIT_TEST(Aggregation_ResultDistinctCountRI_GroupByL) {
+        TAggregationTestCase testCase;
+        testCase.SetQuery(R"(
+                SELECT
+                    level, COUNT(DISTINCT resource_id)
+                FROM `/Root/olapStore/olapTable`
+                GROUP BY level
+                ORDER BY level
+            )")
+            .AddExpectedPlanOptions("CombineCore")
+            .SetExpectedReply("[[[0];4600u];[[1];4600u];[[2];4600u];[[3];4600u];[[4];4600u]]")
+            ;
+
+        TestAggregations({ testCase });
+    }
+
     Y_UNIT_TEST(Aggregation_ResultCountAll_FilterL) {
         //https://st.yandex-team.ru/KIKIMR-16073
         return;