diff options
Diffstat (limited to 'sql/sql_update.cc')
| -rw-r--r-- | sql/sql_update.cc | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/sql/sql_update.cc b/sql/sql_update.cc index 96b1ac67b49..8a9feb1b3f8 100644 --- a/sql/sql_update.cc +++ b/sql/sql_update.cc @@ -1026,9 +1026,17 @@ int mysql_multi_update_prepare(THD *thd) /* following need for prepared statements, to run next time multi-update */ thd->lex->sql_command= SQLCOM_UPDATE_MULTI; - /* open tables and create derived ones, but do not lock and fill them */ + /* + Open tables and create derived ones, but do not lock and fill them yet. + + During prepare phase acquire only S metadata locks instead of SW locks to + keep prepare of multi-UPDATE compatible with concurrent LOCK TABLES WRITE + and global read lock. + */ if ((original_multiupdate && - open_tables(thd, &table_list, &table_count, 0)) || + open_tables(thd, &table_list, &table_count, + (thd->stmt_arena->is_stmt_prepare() ? + MYSQL_OPEN_FORCE_SHARED_MDL : 0))) || mysql_handle_derived(lex, &mysql_derived_prepare)) DBUG_RETURN(TRUE); /* |