"Min/Max Optimization for Queries with Group By Clause"
mysql-test/r/group_min_max.result:
Added new test
mysql-test/t/group_min_max.test:
Added new test & comments
sql/item.h:
Remove processor methods that are no longer used.
sql/item_sum.cc:
Remove processor methods that are no longer used.
sql/item_sum.h:
Remove processor methods that are no longer used.
sql/opt_range.cc:
- the test procedure no longer needs to build lists and to traverse the expression trees
- all usable indexes are tested and the bes one is chosen
- added/edited function comments
sql/sql_select.cc:
Modified make_sum_func_list() so it can be reused in the test for MIN/MAX optimization.
sql/sql_select.h:
Modified make_sum_func_list() so it can be reused in the test for MIN/MAX optimization.
- after-review changes
- merged with the source tree from 204-08-27
mysql-test/r/distinct.result:
Different plans due to group-by optimization.
sql/ha_myisam.cc:
More general interface to key_copy.
sql/handler.cc:
More general interface to key_copy.
sql/item.cc:
New method to collect all Item_field objects. Used by Item::walk.
sql/item.h:
Several methods to collect different kinds of items from expression trees.
Used by Item::walk.
sql/item_sum.cc:
Added helper to collect Item_sum objects.
sql/item_sum.h:
Methods to collect and test Item_sum objects.
sql/key.cc:
More general interface to key_copy and key_restore.
sql/mysql_priv.h:
More general interface to key_copy and key_restore.
sql/opt_range.cc:
Complete implementaion of WL#1724 "Min/Max Optimization for Queries with Group By Clause".
sql/opt_range.h:
Complete implementaion of WL#1724 "Min/Max Optimization for Queries with Group By Clause".
sql/opt_sum.cc:
simple_pred is re-used in opt_range.cc
sql/sql_acl.cc:
More general interface to key_copy and key_restore.
sql/sql_handler.cc:
More general interface to key_copy.
sql/sql_insert.cc:
More general interface to key_copy.
sql/sql_select.cc:
Changes to hook the new QUICK_GROUP_MIN_MAX_SELECT due to two differences from all other
quick selects:
1)
This quick select may be created (and used) even if there is no WHERE clause.
Several places assumed that a QUICK_SELECT is constructed only if there is a WHERE clause,
which had to be changed so that QUICK_GROUP_MIN_MAX can be used.
2)
Unlike all other quick selects, this QUICK_GROUP_MIN_MAX_SELECT operates for GROUP BY queries.
Since for the caller the quick select already produces one result tuple per group, there is
no need to call end_send_group, instead we have to call end_send as for a regular quick select.
sql/sql_select.h:
simple_pred is re-used in opt_range.cc
