diff options
Diffstat (limited to 'sql/sql_show.cc')
| -rw-r--r-- | sql/sql_show.cc | 19 |
1 files changed, 6 insertions, 13 deletions
diff --git a/sql/sql_show.cc b/sql/sql_show.cc index bcc799dce7e..10d8ed23a46 100644 --- a/sql/sql_show.cc +++ b/sql/sql_show.cc @@ -7988,20 +7988,13 @@ bool get_schema_tables_result(JOIN *join, if (table_list->schema_table && thd->fill_information_schema_tables()) { /* - Note, currently I_S tables are filled once per query. - This needs to be changed if if make_cond_for_info_schema() - will preserve outer fields (and thus I_S content will depend on - the outer subquery) - in this new case I_S tables will need to - be re-populated here. - - And in that case, get_all_tables() might be called O(N^2) times - (in self-join of TABLES, for example) and it will allocate - table names on THD::mem_root O(N^2) times. To fix it, get_all_tables - needs to be fixed to use a local memroot, that is reset or destroyed - between get_all_tables invocations. Or fixed not to allocate - table names on THD::memroot if these names don't satisfy lookup_field + I_S tables only need to be re-populated if make_cond_for_info_schema() + preserves outer fields */ - const bool is_subselect= false; + bool is_subselect= &lex->unit != lex->current_select->master_unit() && + lex->current_select->master_unit()->item && + tab->select_cond && + tab->select_cond->used_tables() & OUTER_REF_TABLE_BIT; /* A value of 0 indicates a dummy implementation */ if (table_list->schema_table->fill_table == 0) |