diff options
Diffstat (limited to 'sql/sql_select.h')
| -rw-r--r-- | sql/sql_select.h | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/sql/sql_select.h b/sql/sql_select.h index c8efb26684c..a8081b8d6e3 100644 --- a/sql/sql_select.h +++ b/sql/sql_select.h @@ -1206,7 +1206,17 @@ public: Indicates that grouping will be performed on the result set during query execution. This field belongs to query execution. - @see make_group_fields, alloc_group_fields, JOIN::exec + If 'sort_and_group' is set, then the optimizer is going to use on of + the following algorithms to resolve GROUP BY. + + - If one table, sort the table and then calculate groups on the fly. + - If more than one table, create a temporary table to hold the join, + sort it and then resolve group by on the fly. + + The 'on the fly' calculation is done in end_send_group() + + @see make_group_fields, alloc_group_fields, JOIN::exec, + setup_end_select_func */ bool sort_and_group; bool first_record,full_join, no_field_update; @@ -1585,7 +1595,7 @@ public: bool make_range_rowid_filters(); bool init_range_rowid_filters(); bool make_sum_func_list(List<Item> &all_fields, List<Item> &send_fields, - bool before_group_by, bool recompute= FALSE); + bool before_group_by); /// Initialzes a slice, see comments for ref_ptrs above. Ref_ptr_array ref_ptr_array_slice(size_t slice_num) |