From c4136bc3ed2fea6f8f2bdcfc8f1329f374fe9082 Mon Sep 17 00:00:00 2001
From: ivanmorozov <ivanmorozov@yandex-team.com>
Date: Fri, 22 Sep 2023 09:59:05 +0300
Subject: additional verification

---
 .../columnshard/engines/scheme/column_features.cpp | 23 ++++++++++------------
 .../columnshard/engines/scheme/column_features.h   |  5 +++--
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/ydb/core/tx/columnshard/engines/scheme/column_features.cpp b/ydb/core/tx/columnshard/engines/scheme/column_features.cpp
index dd6341ec7a2..f039fb78147 100644
--- a/ydb/core/tx/columnshard/engines/scheme/column_features.cpp
+++ b/ydb/core/tx/columnshard/engines/scheme/column_features.cpp
@@ -23,20 +23,17 @@ NArrow::NTransformation::ITransformer::TPtr TColumnFeatures::GetLoadTransformer(
 }
 
 std::shared_ptr<NKikimr::NOlap::TColumnLoader> TColumnFeatures::GetLoader(const TIndexInfo& info) const {
-    if (!LoaderCache) {
-        NArrow::NTransformation::ITransformer::TPtr transformer = GetLoadTransformer();
-        auto schema = info.GetColumnSchema(ColumnId);
-        if (!transformer) {
-            LoaderCache = std::make_shared<TColumnLoader>(transformer,
-                std::make_shared<NArrow::NSerialization::TBatchPayloadDeserializer>(schema),
-                schema, ColumnId);
-        } else {
-            LoaderCache = std::make_shared<TColumnLoader>(transformer,
-                std::make_shared<NArrow::NSerialization::TFullDataDeserializer>(),
-                schema, ColumnId);
-        }
+    NArrow::NTransformation::ITransformer::TPtr transformer = GetLoadTransformer();
+    auto schema = info.GetColumnSchema(ColumnId);
+    if (!transformer) {
+        return std::make_shared<TColumnLoader>(transformer,
+            std::make_shared<NArrow::NSerialization::TBatchPayloadDeserializer>(schema),
+            schema, ColumnId);
+    } else {
+        return std::make_shared<TColumnLoader>(transformer,
+            std::make_shared<NArrow::NSerialization::TFullDataDeserializer>(),
+            schema, ColumnId);
     }
-    return LoaderCache;
 }
 
 std::optional<NKikimr::NOlap::TColumnFeatures> TColumnFeatures::BuildFromProto(const NKikimrSchemeOp::TOlapColumnDescription& columnInfo, const ui32 columnId) {
diff --git a/ydb/core/tx/columnshard/engines/scheme/column_features.h b/ydb/core/tx/columnshard/engines/scheme/column_features.h
index 24e07ac7c61..d974810a9cc 100644
--- a/ydb/core/tx/columnshard/engines/scheme/column_features.h
+++ b/ydb/core/tx/columnshard/engines/scheme/column_features.h
@@ -89,6 +89,8 @@ public:
         , ColumnId(columnId)
     {
         Y_VERIFY(ExpectedSchema);
+        auto fieldsCountStr = ::ToString(ExpectedSchema->num_fields());
+        Y_VERIFY(ExpectedSchema->num_fields() == 1, "%s", fieldsCountStr.data());
         Y_VERIFY(Deserializer);
     }
 
@@ -96,7 +98,7 @@ public:
         return ColumnId;
     }
 
-    std::shared_ptr<arrow::Schema> GetExpectedSchema() const {
+    const std::shared_ptr<arrow::Schema>& GetExpectedSchema() const {
         return ExpectedSchema;
     }
 
@@ -121,7 +123,6 @@ private:
     const ui32 ColumnId;
     std::optional<NArrow::TCompression> Compression;
     std::optional<NArrow::NDictionary::TEncodingSettings> DictionaryEncoding;
-    mutable std::shared_ptr<TColumnLoader> LoaderCache;
 public:
     TColumnFeatures(const ui32 columnId)
         : ColumnId(columnId)
-- 
cgit v1.3