diff options
Diffstat (limited to 'sql/opt_range.cc')
| -rw-r--r-- | sql/opt_range.cc | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/sql/opt_range.cc b/sql/opt_range.cc index 12e5c60312b..812d5a41cbc 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -6878,6 +6878,7 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree) SEL_ARG *cur_index_tree= NULL; ha_rows cur_quick_prefix_records= 0; uint cur_param_idx; + key_map cur_used_key_parts; for (uint cur_index= 0 ; cur_index_info != cur_index_info_end ; cur_index_info++, cur_index++) @@ -6925,17 +6926,25 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree) else if (join->select_distinct) { select_items_it.rewind(); + cur_used_key_parts.clear_all(); while ((item= select_items_it++)) { item_field= (Item_field*) item; /* (SA5) already checked above. */ /* Find the order of the key part in the index. */ key_part_nr= get_field_keypart(cur_index_info, item_field->field); + /* + Check if this attribute was already present in the select list. + If it was present, then its corresponding key part was alredy used. + */ + if (cur_used_key_parts.is_set(key_part_nr)) + continue; if (key_part_nr < 1 || key_part_nr > join->fields_list.elements) goto next_index; cur_part= cur_index_info->key_part + key_part_nr - 1; cur_group_prefix_len+= cur_part->store_length; + cur_used_key_parts.set_bit(key_part_nr); + ++cur_group_key_parts; } - cur_group_key_parts= join->fields_list.elements; } else DBUG_ASSERT(FALSE); |