diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index cb5a0604733..f146fc25126 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -7801,6 +7801,30 @@ SEL_TREE *Item_func_in::get_func_mm_tree(RANGE_OPT_PARAM *param, if (array->count > NOT_IN_IGNORE_THRESHOLD || !value_item) DBUG_RETURN(0); + /* + If this is "unique_key NOT IN (...)", do not consider it sargable (for + any index, not just the unique one). The logic is as follows: + - if there are only a few constants, this condition is not selective + (unless the table is also very small in which case we won't gain + anything) + - If there are a lot of constants, the overhead of building and + processing enormous range list is not worth it. + */ + if (param->using_real_indexes) + { + key_map::Iterator it(field->key_start); + uint key_no; + while ((key_no= it++) != key_map::Iterator::BITMAP_END) + { + KEY *key_info= &field->table->key_info[key_no]; + if (key_info->user_defined_key_parts == 1 && + (key_info->flags & HA_NOSAME)) + { + DBUG_RETURN(0); + } + } + } + /* Get a SEL_TREE for "(-inf|NULL) < X < c_0" interval. */ uint i=0; do |