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3 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Michael Widenius
|
e63b5546c5 |
Implementation of MWL#172: Add support for prepared statements to HANDLER READ
It includes speed optimizations for HANDLER READ by caching as much as possible in HANDLER OPEN Other things: - Added mysqld option --disable-thr-alarm to be able to benchmark things without thr_alarm - Changed 'Locked' state to 'System lock' and 'Table lock' (these where used in the code but never shown to end user) - Better error message if mysql_install_db.sh fails - Moved handler function prototypes to sql_handler.h - Remove not anymore used 'thd->locked' member include/thr_alarm.h: Added my_disable_thr_alarm include/thr_lock.h: Add new member to THR_LOCK_DATA to remember original lock type state. This is needed as thr_unlock() resets type to TL_UNLOCK. mysql-test/include/check_no_concurrent_insert.inc: Locked -> Table lock mysql-test/include/handler.inc: Locked -> Table lock mysql-test/r/handler_innodb.result: Updated results for new tests mysql-test/r/handler_myisam.result: Updated results for new tests mysql-test/r/sp-threads.result: Locked -> Table lock mysql-test/suite/binlog/t/binlog_stm_row.test: Locked -> Table lock mysql-test/suite/funcs_1/datadict/processlist_val.inc: Locked -> Table lock mysql-test/suite/pbxt/t/lock_multi.test: Locked -> Table lock mysql-test/suite/sys_vars/r/concurrent_insert_func.result: Locked -> Table lock mysql-test/suite/sys_vars/t/concurrent_insert_func.test: Locked -> Table lock mysql-test/suite/sys_vars/t/delayed_insert_limit_func.test: Locked -> Table lock mysql-test/suite/sys_vars/t/query_cache_wlock_invalidate_func.test: Locked -> Table lock mysql-test/suite/sys_vars/t/sql_low_priority_updates_func.test: Locked -> Table lock mysql-test/t/insert_notembedded.test: Locked -> Table lock mysql-test/t/lock_multi.test: Locked -> Table lock mysql-test/t/merge-big.test: Locked -> Table lock mysql-test/t/multi_update.test: Locked -> Table lock mysql-test/t/query_cache_28249.test: Locked -> Table lock mysql-test/t/sp_notembedded.test: Locked -> Table lock mysql-test/t/sp_sync.test: Locked -> Table lock mysql-test/t/status.test: Locked -> Table lock mysql-test/t/trigger_notembedded.test: Locked -> Table lock mysys/thr_alarm.c: Added option to disable thr_alarm mysys/thr_lock.c: Detect loops scripts/mysql_install_db.sh: Give better error message if something goes wrong sql/Makefile.am: Added sql_handler.h sql/lock.cc: Split functions to allow one to cache value if store_lock() (for HANDLER functions). - Split mysql_lock_tables() into two functions, where first one allocates MYSQL_LOCK and other other one uses it. - Made get_lock_data() an external function. - Added argument to mysql_unlock_tables() to not free sql_lock. - Added argument to reset_lock_data() to reset lock structure to initial state (as after get_lock_data()) sql/mysql_priv.h: Moved handler function prototypes to sql_handler.h Added new lock functions. sql/mysqld.cc: Added --thread-alarm startup option sql/net_serv.cc: Don't call vio_blocking() if not needed sql/sql_base.cc: include sql_handler.h sql/sql_class.cc: include sql_handler.h Remove not anymore used 'thd->locked' member sql/sql_class.h: Remove not anymore used 'thd->locked' member sql/sql_db.cc: include sql_handler.h sql/sql_delete.cc: include sql_handler.h sql/sql_handler.cc: Rewrote all code to use SQL_HANDLER instead of TABLE_LIST (original interface) Rewrote mysql_ha_open() to cache all things from TABLE_LIST and items for field list, where etc. In mysql_ha_open() also cache MYSQL_LOCK structure from get_lock_data(). Split functions into smaller sub functions (needed to be able to implement mysql_ha_read_prepare()) Added mysql_ha_read_prepare() to allow one to prepare HANDLER READ. sql/sql_handler.h: Interface to sql_handler.cc sql/sql_parse.cc: include sql_handler.h sql/sql_prepare.cc: Added mysql_test_handler_read(), prepare for HANDLER READ sql/sql_rename.cc: include sql_handler.h sql/sql_show.cc: Removed usage of thd->locked sql/sql_table.cc: include sql_handler.h sql/sql_trigger.cc: include sql_handler.h |
||
Bjorn Munch
|
909f0bf94a |
Follow-up to Bug #55582 which allows checking strings in if
Simplified cases where a select was used to compare variable against '' |
||
Dmitry Lenev
|
0a35e5bd18 |
A 5.1-only version of fix for bug #46947 "Embedded SELECT
without FOR UPDATE is causing a lock". SELECT statements with subqueries referencing InnoDB tables were acquiring shared locks on rows in these tables when they were executed in REPEATABLE-READ mode and with statement or mixed mode binary logging turned on. This was a regression which were introduced when fixing bug 39843. The problem was that for tables belonging to subqueries parser set TL_READ_DEFAULT as a lock type. In cases when statement/mixed binary logging at open_tables() time this type of lock was converted to TL_READ_NO_INSERT lock at open_tables() time and caused InnoDB engine to acquire shared locks on reads from these tables. Although in some cases such behavior was correct (e.g. for subqueries in DELETE) in case of SELECT it has caused unnecessary locking. This patch implements minimal version of the fix for the specific problem described in the bug-report which supposed to be not too risky for pushing into 5.1 tree. The 5.5 tree already contains a more appropriate solution which also addresses other related issues like bug 53921 "Wrong locks for SELECTs used stored functions may lead to broken SBR". This patch tries to solve the problem by ensuring that TL_READ_DEFAULT lock which is set in the parser for tables participating in subqueries at open_tables() time is interpreted as TL_READ_NO_INSERT or TL_READ. TL_READ is used only if we know that this is a SELECT and that this particular table is not used by a stored function. Test coverage is added for both InnoDB and MyISAM. This patch introduces an "incompatible" change in locking scheme for subqueries used in SELECT ... FOR UPDATE and SELECT .. IN SHARE MODE. In 4.1 (as well as in 5.0 and 5.1 before fix for bug 39843) the server would use a snapshot InnoDB read for subqueries in SELECT FOR UPDATE and SELECT .. IN SHARE MODE statements, regardless of whether the binary log is on or off. If the user required a different type of read (i.e. locking read), he/she could request so explicitly by providing FOR UPDATE/IN SHARE MODE clause for each individual subquery. The patch for bug 39843 broke this behaviour (which was not documented or tested), and started to use locking reads for all subqueries in SELECT ... FOR UPDATE/IN SHARE MODE. This patch restores 4.1 behaviour. This patch should be mostly null-merged into 5.5 tree. mysql-test/include/check_concurrent_insert.inc: Added auxiliary script which allows to check if statement reading table allows concurrent inserts in it. mysql-test/include/check_no_concurrent_insert.inc: Added auxiliary script which allows to check that statement reading table doesn't allow concurrent inserts in it. mysql-test/include/check_no_row_lock.inc: Added auxiliary script which allows to check if statement reading table doesn't take locks on its rows. mysql-test/include/check_shared_row_lock.inc: Added auxiliary script which allows to check if statement reading table takes shared locks on some of its rows. mysql-test/r/bug39022.result: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/r/innodb_mysql_lock2.result: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/r/lock_sync.result: Added coverage for handling of locking in various cases when we read data from MyISAM tables. mysql-test/t/bug39022.test: After bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock' was fixed test case for bug 39022 has to be adjusted in order to trigger execution path on which original problem was encountered. mysql-test/t/innodb_mysql_lock2.test: Added coverage for handling of locking in various cases when we read data from InnoDB tables (includes test case for bug #46947 'Embedded SELECT without FOR UPDATE is causing a lock'). mysql-test/t/lock_sync.test: Added coverage for handling of locking in various cases when we read data from MyISAM tables. sql/mysql_priv.h: Function read_lock_type_for_table() now takes pointers to LEX and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. sql/sql_base.cc: Changed read_lock_type_for_table() to return a weak TL_READ type of lock in cases when we are executing SELECT (and so won't update tables directly) and table doesn't belong to statement's prelocking list and thus can't be used by a stored function. It is OK to do so since in this case table won't be used by statement or function call which will be written to the binary log, so serializability requirements for it can be relaxed. One of results from this change is that SELECTs on InnoDB tables no longer takes shared row locks for tables which are used in subqueries (i.e. bug #46947 is fixed). Another result is that for similar SELECTs on MyISAM tables concurrent inserts are allowed. In order to implement this change signature of read_lock_type_for_table() function was changed to take pointers to LEX and TABLE_LIST objects. sql/sql_update.cc: Function read_lock_type_for_table() now takes pointers to LEX and TABLE_LIST elements as its arguments since to correctly determine lock type it needs to know what statement is being performed and whether table element for which lock type to be determined belongs to prelocking list. |