From 3e41c82df157e65ebe9edbc1b761b79fd6127f8e Mon Sep 17 00:00:00 2001
From: kssenii <sumarokovakseniia@mail.ru>
Date: Thu, 8 Apr 2021 23:38:27 +0000
Subject: [PATCH] Add mutex to tryGetTable only for materialized table (not
 nested)

---
 src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.cpp | 2 ++
 src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.h   | 1 +
 2 files changed, 3 insertions(+)

diff --git a/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.cpp b/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.cpp
index dac33e00b3c..6c746855b89 100644
--- a/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.cpp
+++ b/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.cpp
@@ -122,6 +122,8 @@ StoragePtr DatabaseMaterializePostgreSQL::tryGetTable(const String & name, const
         }
     }
 
+    /// Note: In select query we call MaterializePostgreSQL table and it calls tryGetTable from its nested.
+    std::lock_guard lock(tables_mutex);
     auto table = materialized_tables.find(name);
     /// Here it is possible that nested table is temporarily out of reach, but return storage anyway,
     /// it will not allow to read if nested is unavailable at the moment
diff --git a/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.h b/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.h
index cf9024494f9..f3d4535866a 100644
--- a/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.h
+++ b/src/Databases/PostgreSQL/DatabaseMaterializePostgreSQL.h
@@ -66,6 +66,7 @@ private:
 
     std::shared_ptr<PostgreSQLReplicationHandler> replication_handler;
     std::map<std::string, StoragePtr> materialized_tables;
+    mutable std::mutex tables_mutex;
 };
 
 }