additional logging and fix test cases

3 files changed, 25 insertions, 3 deletions

diff --git a/ydb/core/formats/arrow/size_calcer.cpp b/ydb/core/formats/arrow/size_calcer.cpp
index 90760a51d07..34a5c4fff14 100644
--- a/ydb/core/formats/arrow/size_calcer.cpp
+++ b/ydb/core/formats/arrow/size_calcer.cpp
@@ -190,8 +190,9 @@ bool TSerializedBatch::BuildWithLimit(std::shared_ptr<arrow::RecordBatch> batch,
         TSerializedBatch localSbR = TSerializedBatch::Build(batch->Slice(delta, length - delta));
         if (localSbL.GetSize() > sizeLimit || localSbR.GetSize() > sizeLimit) {
             if (errorMessage) {
-                *errorMessage = TStringBuilder() << "original batch too big: " << sb.GetSize() << " and after 2 parts split we have: " <<
-                    localSbL.GetSize() << " / " << localSbR.GetSize() << " part sizes. Its unexpected";
+                *errorMessage = TStringBuilder() << "original batch too big: " << sb.GetSize() << " and after 2 parts split we have: "
+                    << localSbL.GetSize() << "(" << localSbL.GetRowsCount() << ")" << " / "
+                    << localSbR.GetSize() << "(" << localSbR.GetRowsCount() << ")" << " part sizes. Its unexpected for limit " << sizeLimit;
             }
             return false;
         }
diff --git a/ydb/core/kqp/ut/olap/kqp_olap_ut.cpp b/ydb/core/kqp/ut/olap/kqp_olap_ut.cpp
index 258dd45e120..4789a2ba675 100644
--- a/ydb/core/kqp/ut/olap/kqp_olap_ut.cpp
+++ b/ydb/core/kqp/ut/olap/kqp_olap_ut.cpp
@@ -2312,7 +2312,7 @@ Y_UNIT_TEST_SUITE(KqpOlap) {
     }
 
     Y_UNIT_TEST(Aggregation_ResultCountExpr) {
-        NColumnShard::TLimits::SetMaxBlobSize(10000);
+        auto g = NColumnShard::TLimits::MaxBlobSizeGuard(10000);
         TAggregationTestCase testCase;
         testCase.SetQuery(R"(
                     SELECT
diff --git a/ydb/core/tx/columnshard/defs.h b/ydb/core/tx/columnshard/defs.h
index d280261262f..30a248242b1 100644
--- a/ydb/core/tx/columnshard/defs.h
+++ b/ydb/core/tx/columnshard/defs.h
@@ -22,6 +22,27 @@ struct TLimits {
     static ui64 GetMaxBlobSize();
     static void SetMaxBlobSize(const ui64 value);
 
+    class TMaxBlobSizeGuard: TNonCopyable {
+    private:
+        const ui64 Size;
+        const ui64 Original;
+    public:
+        TMaxBlobSizeGuard(const ui64 value)
+            : Size(value)
+            , Original(GetBlobSizeLimit())
+        {
+            SetMaxBlobSize(Size);
+        }
+
+        ~TMaxBlobSizeGuard() {
+            SetMaxBlobSize(Original);
+        }
+    };
+
+    static TMaxBlobSizeGuard MaxBlobSizeGuard(const ui64 value) {
+        return TMaxBlobSizeGuard(value);
+    }
+
     TControlWrapper MinInsertBytes;
     TControlWrapper MaxInsertBytes;
     TControlWrapper InsertTableSize;