diff options
Diffstat (limited to 'sql/sql_select.cc')
| -rw-r--r-- | sql/sql_select.cc | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 3f1432914a0..9dacb2c2ce4 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -1231,13 +1231,22 @@ JOIN::optimize() (!group_list && tmp_table_param.sum_func_count)) order=0; - // Can't use sort on head table if using row cache + // Can't use sort on head table if using join buffering if (full_join) { - if (group_list) - simple_group=0; - if (order) - simple_order=0; + TABLE *stable= (sort_by_table == (TABLE *) 1 ? + join_tab[const_tables].table : sort_by_table); + /* + FORCE INDEX FOR ORDER BY can be used to prevent join buffering when + sorting on the first table. + */ + if (!stable || !stable->force_index_order) + { + if (group_list) + simple_group= 0; + if (order) + simple_order= 0; + } } /* |