The problem was that when there was no MIN or MAX function, after finding the
group prefix based on the DISTINCT or GROUP BY attributes we did not search further
for a key in the group that satisfies the equi-join conditions on attributes that
follow the group attributes. Thus we ended up with the wrong rows, and subsequent
calls to select_cond->val_int() in evaluate_join_record() were filtering those
rows. Hence - the query result set was empty.
The problem occured both for GROUP BY queries without MIN/MAX and for queries
with DISTINCT (which were internally executed as GROUP BY queries).
mysql-test/r/group_min_max.result:
Added test result for BUG#11044. Notice that the group by query is
equivalent to the distinct query and both are executed via the same
algorithm.
mysql-test/t/group_min_max.test:
Added test for BUG#11044. Notice that the group by query is
equivalent to the distinct query and both are executed via the
same algorithm.
sql/opt_range.cc:
* Use the extended prefix in QUICK_GROUP_MIN_MAX_SELECT::get_next()
to find keys that satisfy equality conditions in the case when there is
no MIN or MAX function.
* Corrected some method comments.
* Corrected debug printout of cost information.
sql/opt_range.cc:
Fix for bug #9798: Rollup crash with InnoDB in setup_sum_funcs().
Disable mix/max group by optimization for queries with rollup for now.
Note: the actual bug was hidden; if this optimization works with rollup
queries we will have to change some code:
the problem is that we call the join->make_sum_func_list() function against
changed thd->mem_root (see SQL_SELECT::test_quick_select()) which creates some
items for rollup, then we free that mem_root, then we try to reuse (free) those
items.
The problem was in that the code that analyses the applicability of the
QUICK_GROUP_MIN_MAX access method for DISTINC queries assumed that there
are no duplicate column references in the DISTINCT clause, and it added
non-exiting key parts for the duplicate column references.
The solution adds a test to check whether the select list already contained
a field with the same name. If such field was already present, then it was
already decided to use its key part for index access. In this such case we
must skip the duplicate field instead of counting it as a new field.
mysql-test/r/group_min_max.result:
Added test results for BUG#8532.
mysql-test/t/group_min_max.test:
Added tests for BUG#8532.
sql/opt_range.cc:
The problem was in that the code that analyses the applicability of the
QUICK_GROUP_MIN_MAX access method for DISTINC queries assumed that there
are no duplicate column references in the DISTINCT clause, and it added
non-exiting key parts for the duplicate column references.
The solution adds a test to check whether the select list already contained
a field with the same name. If such field was already present, then it was
already decided to use its key part for index access. In this such case we
must skip the duplicate field instead of counting it as a new field.
Split TABLE to TABLE and TABLE_SHARE (TABLE_SHARE is still allocated as part of table, will be fixed soon)
Created Field::make_field() and made Field_num::make_field() to call this
Added 'TABLE_SHARE->db' that points to database name; Changed all usage of table_cache_key as database name to use this instead
Changed field->table_name to point to pointer to alias. This allows us to change alias for a table by just updating one pointer.
Renamed TABLE_SHARE->real_name to table_name
Renamed TABLE->table_name to alias
Renamed TABLE_LIST->real_name to table_name
include/myisam.h:
Added const before names
mysql-test/r/group_min_max.result:
Make results repeatable
mysql-test/t/group_min_max.test:
Make results repeatable
sql/field.cc:
Created Field::make_field() and made Field_num::make_field() to call this
Use TABLE_SHARE
Use sql_strmake() instead of sql_memdup() to simplify code
sql/field.h:
Changed table_name to be pointer to table_name. This allows us to change alias for all fields by just changing one pointer.
Use TABLE_SHARE
sql/field_conv.cc:
Use TABLE_SHARE
sql/filesort.cc:
Use TABLE_SHARE
sql/ha_berkeley.cc:
Use TABLE_SHARE
sql/ha_heap.cc:
Use TABLE_SHARE
sql/ha_innodb.cc:
Use TABLE_SHARE
sql/ha_myisam.cc:
Use TABLE_SHARE
sql/ha_myisammrg.cc:
Use TABLE_SHARE
Change some pointer handling to use const char*
sql/ha_ndbcluster.cc:
Use TABLE_SHARE
sql/handler.cc:
Use TABLE_SHARE
sql/item.cc:
Use TABLE_SHARE
sql/item_func.cc:
Use TABLE_SHARE
sql/item_subselect.cc:
Use TABLE_SHARE
sql/item_sum.cc:
Use TABLE_SHARE
sql/key.cc:
Use TABLE_SHARE
sql/lock.cc:
Use TABLE_SHARE
sql/log_event.cc:
real_name -> table_name
sql/mysql_priv.h:
Use TABLE_SHARE
sql/opt_range.cc:
Use TABLE_SHARE
sql/opt_sum.cc:
Use TABLE_SHARE
sql/records.cc:
Use TABLE_SHARE
sql/repl_failsafe.cc:
real_name -> table_name
sql/slave.cc:
Use TABLE_SHARE
sql/sp.cc:
Use TABLE_SHARE
sql/sp_head.cc:
real_name -> table_name
sql/sql_acl.cc:
Use TABLE_SHARE
removed unnecessary assert
fixed indentation
changed some char * -> const char*
sql/sql_acl.h:
changed some char* -> const char*
sql/sql_base.cc:
Use TABLE_SHARE
sql/sql_cache.cc:
Use TABLE_SHARE
sql/sql_class.cc:
Use TABLE_SHARE
sql/sql_db.cc:
real_name -> table_name
sql/sql_delete.cc:
Use TABLE_SHARE
sql/sql_derived.cc:
Use TABLE_SHARE
sql/sql_handler.cc:
Use TABLE_SHARE
sql/sql_help.cc:
Use TABLE_SHARE
sql/sql_insert.cc:
Use TABLE_SHARE
sql/sql_load.cc:
Use TABLE_SHARE
sql/sql_parse.cc:
Use TABLE_SHARE
sql/sql_rename.cc:
real_name -> table_name
sql/sql_select.cc:
Use TABLE_SHARE
table->blob_fields now points to field offsets, not fields
tmp_table->table_name now points to alias name
sql/sql_show.cc:
Use TABLE_SHARE
sql/sql_table.cc:
Use TABLE_SHARE
sql/sql_test.cc:
Use TABLE_SHARE
sql/sql_trigger.cc:
Use TABLE_SHARE
sql/sql_udf.cc:
Use TABLE_SHARE
sql/sql_union.cc:
real_name -> table_name
sql/sql_update.cc:
Use TABLE_SHARE
sql/sql_view.cc:
Use TABLE_SHARE
sql/table.cc:
Split TABLE to TABLE and TABLE_SHARE
Changed blob_field to be field offsets instead of pointer to fields
Only initialize table->s->default_values with default record (not all table->record[#])
Some indentation changes
sql/table.h:
Split TABLE to TABLE and TABLE_SHARE
sql/tztime.cc:
real_name -> table_name
sql/unireg.cc:
Use TABLE_SHARE
sql/unireg.h:
Use TABLE_SHARE
mysql-test/r/group_min_max.result:
Test results for BUG#6303
mysql-test/t/group_min_max.test:
Ucommented tests for BUG#6303
sql/opt_range.cc:
Comment fix
BitKeeper/etc/ignore:
Added stamp-h1.in stamp-h2.in to the ignore list
mysql-test/t/group_min_max.test:
- Added test for BUG#6303
- Added test for MIN/MAX optimizable queries with subqueries
sql/opt_range.cc:
- check_group_min_max_predicates should not be called when there is no MIN/MAX function
- skip queries from GROUP BY with MIN/MAX optimization when there is a subselect in the WHERE clause
"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
