KIKIMR-19582: dont merge in case fully empty intervals

2 files changed, 17 insertions, 1 deletions

diff --git a/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.cpp b/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.cpp
index 28a82d5e6b..464127ef02 100644
--- a/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.cpp
+++ b/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.cpp
@@ -42,6 +42,19 @@ private:
             LastPK = nullptr;
         }
     }
+
+    bool EmptyFiltersOnly() const {
+        for (auto&& [_, i] : Sources) {
+            if (!i->GetFilterStageData().GetBatch() || !i->GetFilterStageData().GetBatch()->num_rows()) {
+                continue;
+            }
+            auto f = i->GetFilterStageData().GetNotAppliedEarlyFilter();
+            if (!f || !f->IsTotalDenyFilter()) {
+                return false;
+            }
+        }
+        return true;
+    }
 protected:
     virtual bool DoApply(NOlap::IDataReader& indexedDataRead) const override {
         AFL_DEBUG(NKikimrServices::TX_COLUMNSHARD_SCAN)("event", "DoApply")("interval_idx", MergingContext->GetIntervalIdx());
@@ -66,6 +79,10 @@ protected:
             AFL_VERIFY(!!LastPK == (!!ResultBatch && ResultBatch->num_rows()));
             return true;
         }
+        if (EmptyFiltersOnly()) {
+            ResultBatch = NArrow::MakeEmptyBatch(Context->GetProgramInputColumns()->GetSchema());
+            return true;
+        }
         std::shared_ptr<NIndexedReader::TMergePartialStream> merger = Context->BuildMerger();
         for (auto&& [_, i] : Sources) {
             if (auto rb = i->GetBatch()) {
diff --git a/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.h b/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.h
index a86845b0fe..50f7fe76a8 100644
--- a/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.h
+++ b/ydb/core/tx/columnshard/engines/reader/plain_reader/interval.h
@@ -68,7 +68,6 @@ private:
         return result;
     }
 
-    bool IsSourcesReady();
     std::shared_ptr<NResourceBroker::NSubscribe::TResourcesGuard> ResourcesGuard;
     const ui32 IntervalIdx;
     TAtomicCounter ReadySourcesCount = 0;