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| author | unknown <timour@mysql.com> | 2004-04-16 13:21:08 +0300 |
|---|---|---|
| committer | unknown <timour@mysql.com> | 2004-04-16 13:21:08 +0300 |
| commit | 4c56ede41c6d8148063df723e701281a860ce48e (patch) | |
| tree | 91b90e1956c2035488a4d2b8c7d9dc45e5bc4127 /sql/structs.h | |
| parent | 8468cde4f1e028b380c24d0bac28402678568d81 (diff) | |
| download | mariadb-git-4c56ede41c6d8148063df723e701281a860ce48e.tar.gz | |
Implementation of WL#1469 (Greedy algorithm to search for an optimal execution plan).
mysql-test/r/subselect.result:
Table pre-sorting before optimization makes the optimizer select a different plan, this change fixes the plan.
sql/mysql_priv.h:
Added new status variable last_query_cost that contains the cost of the last compiled query.
sql/mysqld.cc:
* Added new system variable 'plan_search_depth' to control the exhaustiveness of the search for an optimal query plan.
* Added new system variable 'heuristic' to control the use of query optimization heuristic.
* Added new status variable 'last_query_cost' that contains the cost of the last compiled query.
sql/set_var.cc:
* Added new system variable 'plan_search_depth' to control the exhaustiveness of the search for an optimal query plan.
* Added new system variable 'heuristic' to control the use of query optimization heuristic.
sql/sql_class.h:
* Added new system variable 'plan_search_depth' to control the exhaustiveness of the search for an optimal query plan.
* Added new system variable 'heuristic' to control the use of query optimization heuristic.
sql/sql_select.cc:
Added a combined greedy/exhaustive query optimization algorithm.
* The greedy search algorithm is implemented in function 'greedy_search'.
* The exhaustive search with controlled search depth is implemented in function 'find_best_limited_depth', a modification of 'find_best'.
* The selection of the best access path and its cost computation is factored out from 'find_best' into function 'best_access_path'.
* In addition:
- added pre-sorting for the query tables before they get optimized
- factored out the optimization of STRAIGHT_JOIN into a separate procedure
sql/sql_select.h:
Added new field to st_position to support the greedy optimizer.
Added a comment to class JOIN.
sql/sql_show.cc:
Added a case to 'mysqld_show' to print double status variables.
sql/structs.h:
Added a new type of status variables SHOW_DOUBLE
BitKeeper/etc/logging_ok:
Logging to logging@openlogging.org accepted
Diffstat (limited to 'sql/structs.h')
| -rw-r--r-- | sql/structs.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sql/structs.h b/sql/structs.h index 37208e63400..3279428c888 100644 --- a/sql/structs.h +++ b/sql/structs.h @@ -156,8 +156,8 @@ typedef struct st_known_date_time_format { enum SHOW_TYPE { SHOW_UNDEF, - SHOW_LONG, SHOW_LONGLONG, SHOW_INT, SHOW_CHAR, SHOW_CHAR_PTR, SHOW_BOOL, - SHOW_MY_BOOL, SHOW_OPENTABLES, SHOW_STARTTIME, SHOW_QUESTION, + SHOW_LONG, SHOW_LONGLONG, SHOW_INT, SHOW_CHAR, SHOW_CHAR_PTR, SHOW_DOUBLE, + SHOW_BOOL, SHOW_MY_BOOL, SHOW_OPENTABLES, SHOW_STARTTIME, SHOW_QUESTION, SHOW_LONG_CONST, SHOW_INT_CONST, SHOW_HAVE, SHOW_SYS, SHOW_HA_ROWS, #ifdef HAVE_OPENSSL SHOW_SSL_CTX_SESS_ACCEPT, SHOW_SSL_CTX_SESS_ACCEPT_GOOD, |