From bfe2425aadc92071392cc339229270f563a22216 Mon Sep 17 00:00:00 2001 From: unknown Date: Thu, 6 May 2004 15:53:01 +0200 Subject: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). HEAP: Copies the key count to a backup variable and sets the key count to zero. That way, no HEAP function will ever try to touch any index. Re-enabling is done by copying back the backup variable. To avoid memory leak at table close, disable deletes all index trees. Re-enabling must be done with empty indexes and data anyway. Otherwise, the indexes would need to be repaired, wich HEAP is not capable of. MyISAM: Only the key_map is cleared and set. Re-enabling must be done with empty indexes and data. Otherwise, repair needs to be done which will enable all keys persistently. The former implementation disabled only non-unique keys and maked this persistent. The new implementation additionally can disable all keys, but only without making this persistent. Re-enabling all keys can be done without repair, if data file and indexes are empty. heap/heapdef.h: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Pulled hp_clear_keys() out of hp_clear(). heap/hp_clear.c: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Pulled hp_clear_keys() out of hp_clear(). Added the new functions for disabling and enabling keys and to ask for the key state. include/heap.h: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Added a new HP_SHARE element to save the key count while keys are disabled. Added declarations for the new functions. myisam/mi_open.c: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Added the new functions for disabling and enabling keys and to ask for the key state. myisam/myisamdef.h: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Added declarations for the new functions. sql/ha_heap.cc: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Pulled set_keys_for_scanning() out of open(). Added the new functions for disabling and enabling keys and to ask for the key state. sql/ha_heap.h: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Added declarations for the new functions. sql/ha_myisam.cc: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Extended disable_indexes() for all keys and no save. The argument is now 'mode' as it must handle different cases. Extended enable_indexes() for no save. The new feature needs the new argument 'mode' with the same semantics as in disable_indexes(). Added indexes_are_disabled() to ask for the key state. Extended the existing call to enable_indexes() by the new argument. sql/ha_myisam.h: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Modified the declarations of dis-/enable_indexes() for the new argument. Added the declaration of the new function to ask for the key state. sql/handler.h: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Added declarations for the operation modes for the key switching functions. Modified the declarations of dis-/enable_indexes() for the new argument. Added the declaration of the new function to ask for the key state. sql/sql_select.cc: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). In create_myisam_from_heap() take notice of disabled keys and disable them in the new table before copying the data. sql/sql_table.cc: WL#1687 - Optimize UNION DISTINCT ... UNION ALL (again). Modified the calls of dis-/enable_indexes() for the new argument. --- sql/ha_heap.cc | 144 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 137 insertions(+), 7 deletions(-) (limited to 'sql/ha_heap.cc') diff --git a/sql/ha_heap.cc b/sql/ha_heap.cc index 47978d647ec..12b922e6fc0 100644 --- a/sql/ha_heap.cc +++ b/sql/ha_heap.cc @@ -1,4 +1,4 @@ -/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB +/* Copyright (C) 2000,2004 MySQL AB & MySQL Finland AB & TCX DataKonsult AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -47,12 +47,7 @@ int ha_heap::open(const char *name, int mode, uint test_if_locked) if (file) { /* Initialize variables for the opened table */ - btree_keys.clear_all(); - for (uint i= 0 ; i < table->keys ; i++) - { - if (table->key_info[i].algorithm == HA_KEY_ALG_BTREE) - btree_keys.set_bit(i); - } + set_keys_for_scanning(); } return (file ? 0 : 1); } @@ -62,6 +57,33 @@ int ha_heap::close(void) return heap_close(file); } + +/* + Compute which keys to use for scanning + + SYNOPSIS + set_keys_for_scanning() + no parameter + + DESCRIPTION + Set the bitmap btree_keys, which is used when the upper layers ask + which keys to use for scanning. For each btree index the + corresponding bit is set. + + RETURN + void +*/ + +void ha_heap::set_keys_for_scanning(void) +{ + btree_keys.clear_all(); + for (uint i= 0 ; i < table->keys ; i++) + { + if (table->key_info[i].algorithm == HA_KEY_ALG_BTREE) + btree_keys.set_bit(i); + } +} + int ha_heap::write_row(byte * buf) { statistic_increment(ha_write_count,&LOCK_status); @@ -207,6 +229,114 @@ int ha_heap::external_lock(THD *thd, int lock_type) return 0; // No external locking } + +/* + Disable indexes. + + SYNOPSIS + disable_indexes() + mode mode of operation: + HA_KEY_SWITCH_NONUNIQ disable all non-unique keys + HA_KEY_SWITCH_ALL disable all keys + HA_KEY_SWITCH_NONUNIQ_SAVE dis. non-uni. and make persistent + HA_KEY_SWITCH_ALL_SAVE dis. all keys and make persistent + + DESCRIPTION + Disable indexes and clear keys to use for scanning. + + IMPLEMENTATION + HA_KEY_SWITCH_NONUNIQ is not implemented. + HA_KEY_SWITCH_NONUNIQ_SAVE is not implemented with HEAP. + HA_KEY_SWITCH_ALL_SAVE is not implemented with HEAP. + + RETURN + 0 ok + HA_ERR_WRONG_COMMAND mode not implemented. +*/ + +int ha_heap::disable_indexes(uint mode) +{ + int error; + + if (mode == HA_KEY_SWITCH_ALL) + { + if (!(error= heap_disable_indexes(file))) + set_keys_for_scanning(); + } + else + { + /* mode not implemented */ + error= HA_ERR_WRONG_COMMAND; + } + return error; +} + + +/* + Enable indexes. + + SYNOPSIS + enable_indexes() + mode mode of operation: + HA_KEY_SWITCH_NONUNIQ enable all non-unique keys + HA_KEY_SWITCH_ALL enable all keys + HA_KEY_SWITCH_NONUNIQ_SAVE en. non-uni. and make persistent + HA_KEY_SWITCH_ALL_SAVE en. all keys and make persistent + + DESCRIPTION + Enable indexes and set keys to use for scanning. + The indexes might have been disabled by disable_index() before. + The function works only if both data and indexes are empty, + since the heap storage engine cannot repair the indexes. + To be sure, call handler::delete_all_rows() before. + + IMPLEMENTATION + HA_KEY_SWITCH_NONUNIQ is not implemented. + HA_KEY_SWITCH_NONUNIQ_SAVE is not implemented with HEAP. + HA_KEY_SWITCH_ALL_SAVE is not implemented with HEAP. + + RETURN + 0 ok + HA_ERR_CRASHED data or index is non-empty. Delete all rows and retry. + HA_ERR_WRONG_COMMAND mode not implemented. +*/ + +int ha_heap::enable_indexes(uint mode) +{ + int error; + + if (mode == HA_KEY_SWITCH_ALL) + { + if (!(error= heap_enable_indexes(file))) + set_keys_for_scanning(); + } + else + { + /* mode not implemented */ + error= HA_ERR_WRONG_COMMAND; + } + return error; +} + + +/* + Test if indexes are disabled. + + SYNOPSIS + indexes_are_disabled() + no parameters + + RETURN + 0 indexes are not disabled + 1 all indexes are disabled + [2 non-unique indexes are disabled - NOT YET IMPLEMENTED] +*/ + +int ha_heap::indexes_are_disabled(void) +{ + return heap_indexes_are_disabled(file); +} + THR_LOCK_DATA **ha_heap::store_lock(THD *thd, THR_LOCK_DATA **to, enum thr_lock_type lock_type) -- cgit v1.2.1