From 11b6dd0467a1d560fa61330962afb60a0dfc90ba Mon Sep 17 00:00:00 2001
From: Michael Kolupaev <michael.kolupaev@clickhouse.com>
Date: Fri, 16 Jun 2023 06:52:11 +0000
Subject: [PATCH] Fix race condition in ColumnLowCardinality caused by subtly
 broken copy-on-write for the dictionary

---
 src/Columns/ColumnLowCardinality.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Columns/ColumnLowCardinality.h b/src/Columns/ColumnLowCardinality.h
index a5c056153bb3..86ab3d153e97 100644
--- a/src/Columns/ColumnLowCardinality.h
+++ b/src/Columns/ColumnLowCardinality.h
@@ -340,7 +340,7 @@ class ColumnLowCardinality final : public COWHelper<IColumn, ColumnLowCardinalit
         explicit Dictionary(MutableColumnPtr && column_unique, bool is_shared);
         explicit Dictionary(ColumnPtr column_unique, bool is_shared);
 
-        const ColumnPtr & getColumnUniquePtr() const { return column_unique; }
+        const WrappedPtr & getColumnUniquePtr() const { return column_unique; }
         WrappedPtr & getColumnUniquePtr() { return column_unique; }
 
         const IColumnUnique & getColumnUnique() const { return static_cast<const IColumnUnique &>(*column_unique); }