From 60ab3294b1f8107aff82d7bbf97a8697f2499323 Mon Sep 17 00:00:00 2001
From: Nikolai Kochetov <nik-kochetov@yandex-team.ru>
Date: Mon, 12 Mar 2018 19:23:48 +0300
Subject: [PATCH] fix concurrent select from system.parts_columns

---
 dbms/src/Storages/System/StorageSystemPartsColumns.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dbms/src/Storages/System/StorageSystemPartsColumns.cpp b/dbms/src/Storages/System/StorageSystemPartsColumns.cpp
index 16e89824f20..9667399c534 100644
--- a/dbms/src/Storages/System/StorageSystemPartsColumns.cpp
+++ b/dbms/src/Storages/System/StorageSystemPartsColumns.cpp
@@ -63,7 +63,7 @@ void StorageSystemPartsColumns::processNextStorage(MutableColumns & columns, con
 
     NamesAndTypesList columns_list = info.storage->getColumnsList();
     columns_list.insert(std::end(columns_list), std::begin(info.storage->alias_columns), std::end(info.storage->alias_columns));
-    column_defaults = info.storage->column_defaults;
+    const auto & column_defaults = info.storage->column_defaults;
     std::unordered_map<String, ColumnInfo> columns_info;
 
     for (const auto & column : columns_list)