This bug has the same nature as the issues
MDEV-34718: Trigger doesn't work correctly with bulk update
MDEV-24411: Trigger doesn't work correctly with bulk insert
To fix the issue covering all use cases, resetting the thd->bulk_param
temporary to the value nullptr before invoking triggers and restoring
its original value on finishing execution of a trigger is moved to the method
Table_triggers_list::process_triggers
that be invoked ultimately for any kind of triggers.
The patch for MDEV-31340 fixed the following bugs:
MDEV-33084 LASTVAL(t1) and LASTVAL(T1) do not work well with lower-case-table-names=0
MDEV-33085 Tables T1 and t1 do not work well with ENGINE=CSV and lower-case-table-names=0
MDEV-33086 SHOW OPEN TABLES IN DB1 -- is case insensitive with lower-case-table-names=0
MDEV-33088 Cannot create triggers in the database `MYSQL`
MDEV-33103 LOCK TABLE t1 AS t2 -- alias is not case sensitive with lower-case-table-names=0
MDEV-33108 TABLE_STATISTICS and INDEX_STATISTICS are case insensitive with lower-case-table-names=0
MDEV-33109 DROP DATABASE MYSQL -- does not drop SP with lower-case-table-names=0
MDEV-33110 HANDLER commands are case insensitive with lower-case-table-names=0
MDEV-33119 User is case insensitive in INFORMATION_SCHEMA.VIEWS
MDEV-33120 System log table names are case insensitive with lower-cast-table-names=0
Backporting the fixes from 11.5 to 10.5
This is the follow-up patch that removes explicit use of thd->stmt_arena
for memory allocation and replaces it with call of the method
THD::active_stmt_arena_to_use()
Additionally, this patch adds extra DBUG_ASSERT to check that right
query arena is in use.
The bug is that we don't have a a lock on the trigger name, so it is
possible for two threads to try to create the same trigger at the same
time and both thinks that they have succeed.
Same thing can happen with drop trigger or a combinations of create and
drop trigger.
Fixed by adding a mdl lock for the trigger name for the duration of the
create/drop.
The problem is that if table definition cache (TDC) is full of real tables
which are in tables cache, view definition can not stay there so will be
removed by its own underlying tables.
In situation above old mechanism of detection matching definition in PS
and current version always require reprepare and so prevent executing
the PS.
One work around is to increase TDC, other - improve version check for
views/triggers (which is done here). Now in suspicious cases we check:
- timestamp (microseconds) of the view to be sure that version really
have changed;
- time (microseconds) of creation of a trigger related to time
(microseconds) of statement preparation.
There are separate flags DBUG_OFF for disabling the DBUG facility
and ENABLED_DEBUG_SYNC for enabling the DEBUG_SYNC facility.
Let us allow debug builds without DEBUG_SYNC.
Note: For CMAKE_BUILD_TYPE=Debug, CMakeLists.txt will continue to
define ENABLED_DEBUG_SYNC.
Making changes to wsrep_mysqld.h causes large parts of server code to
be recompiled. The reason is that wsrep_mysqld.h is included by
sql_class.h, even tough very little of wsrep_mysqld.h is needed in
sql_class.h. This commit introduces a new header file, wsrep_on.h,
which is meant to be included from sql_class.h, and contains only
macros and variable declarations used to determine whether wsrep is
enabled.
Also, header wsrep.h should only contain definitions that are also
used outside of sql/. Therefore, move WSREP_TO_ISOLATION* and
WSREP_SYNC_WAIT macros to wsrep_mysqld.h.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
Task 6:
We can find the .frm type of file. If it is sequence then is_sequence
passed to dd_frm_type() will be true. Since there is already a check
to give error message if we trigger is on temporary table or view, an
additional condition is added to check if .frm is sequence
(is_sequence==true) and error message is changed to show
"Trigger's '%-.192s' is view, temporary table or sequence" instead of
"Trigger's '%-.192s' is view or temporary table".
Problem:
At some point, we made stored rountines fail at CREATE time
instead of execution time in case of this syntax:
IF unknown_variable
...
END IF
As a result, a trigger created before this change and contained an unknown
variable worked in a bad way after upgrade:
- It was displayed with an empty trigger name by SHOW CREATE TRIGGER
- It was displayed with an empty trigger name by INFORMATION_SCHEMA.TRIGGERS
- An attempt to DROP this trigger returned errors - nothing happened.
- DROP TABLE did not remove the .TRN file corresponding to this broken trigger.
Underlying code observations:
The old code assumed that the trigger name resides in the current lex:
if(thd->lex->spname)
m_trigger_name= &thd->lex->spname->m_name;
This is not always the case. Some SP statements (e.g. IF)
do the following in their beginning:
- create a separate local LEX
- set thd->lex to this new local LEX
- push the new local LEX to the stack in sp_head::m_lex
and the following at the end of the statement:
- pop the previous LEX from the stack sp_head::m_lex
- set thd->lex back to the popped value
So when the parse error happens inside e.g. IF statement, thd->lex->spname
is a NULL pointer, because thd->lex points to the local LEX (without SP name)
rather than the top level LEX (with SP name).
Fix:
- Adding a new method sp_head::find_spname_recursive()
which walks inside the LEX stack sp_head::m_lex from
the top (the newest, most local) to the bottom (the oldest),
and finds the one which contains a non-zero spname pointer.
- Using the new method inside
Deprecated_trigger_syntax_handler::handle_condition():
First it still tests thd->lex->spname (like before this change),
and uses it in case it is not empty.
Otherwise (if thd->lex->spname is empty), it calls
sp_head::find_spname_recursive() to find the LEX with a
non-empty spname inside the LEX stack of the current sphead.
- Rename DDL_IGNORE_LOG_ENTRY_CODE to DDL_LOG_IGNORE_ENTRY_CODE
This makes it similar to all other ddl_log_entry_code's.
- Added some new comments
- ddl_log_revert() now returns != 0 if revert didn't succeed
The reason was that WSREP code in mysql_create_or_drop_trigge() did
jump to an exit label that did not do proper cleanup of state.
Fixed by ensuring that also WSREP code goes trough the cleanup process.
The bug is that we don't have a a lock on the trigger name, so it is
possible for two threads to try to create the same trigger at the same
time and both thinks that they have succeed.
Same thing can happen with drop trigger or a combinations of create and
drop trigger.
Fixed by adding a mdl lock for the trigger name for the duration of the
create/drop.
ALTER TABLE .. RENAME, when used with the inplace algorithm, does:
- Do an inplace or online alter to the new definition
- Rename to new name
- Update triggers.
If update triggers would fail, we would rename the table back.
The problem with this approach is that the table would have the new
definition but the rename would fail. The binary log would also not be
updated.
The solution to this is to very early check if we can rename triggers
and give an error if this would fail.
Both ALTER TABLE ... RENAME and RENAME TABLE is fixed.
This was implemented by moving the pre-check of rename table in triggers
from Table_triggers_list::change_table_name() to
Table_triggers_list::prepare_for_rename().
Before this fix, one would get a 'Trigger ... already exists' when trying
to create a trigger matching the original name and 'Trigger ... does not
exists" when trying to drop it.
Fixes a reported bug in MDEV-25180 Atomic ALTER TABLE
MDEV-25517 Atomic DDL: Assertion `query_arg' in THD::binlog_query
upon DROP TRIGGER
The bug was that the stmt_query variable was not populated
with the query in case of DROP TRIGGER of an orphan trigger
(.TRN file exists & table exists, but the trigger was not in
table->triggers).
The purpose of this task is to ensure that CREATE TRIGGER is atomic
When a trigger is created, we first create a trigger_name.TRN file and then
create or update the table_name.TRG files.
This is done by creating .TRN~ and .TRG~ files and replacing (or creating)
the result files.
The new logic is
- Log CREATE TRIGGER to DDL log, with a marker if old trigger existsted
- If old .TRN or .TRG files exists, make backup copies of these
- Create the new .TRN and .TRG files as before
- Remove the backups
Crash recovery
- If query has been logged to binary log:
- delete any left over backup files
- else
- Delete any old .TRN~ or .TRG~ files
- If there was orignally some triggers (old .TRG file existed)
- If we crashed before creating all backup files
- Delete existing backup files
- else
- Restore backup files
- end
- Delete .TRN and .TRG file (as there was no triggers before
One benefit of the new code is that CREATE OR REPLACE TRIGGER is now
totally atomic even if there existed an old trigger: Either the old
trigger will be replaced or the old one will be left untouched.
Other things:
- If sql_create_definition_file() would fail, there could be memory leaks
in CREATE TRIGGER, DROP TRIGGER or CREATE OR REPLACE TRIGGER. This
is now fixed.
The purpose of this task is to ensure that DROP TRIGGER is atomic.
Description of how atomic drop trigger works:
Logging of DROP TRIGGER
Log the following information:
db
table name
trigger name
xid /* Used to check if query was already logged to binary log */
initial length of the .TRG file
query if there is space for it, if not log a zero length query.
Recovery operations:
- Delete if exists 'database/trigger_name.TRN~'
- If this file existed, it means that we crashed before the trigger
was deleted and there is nothing else to do.
- Get length of .TRG file
- If file length is unchanged, trigger was not dropped. Nothing else to
do.
- Log original query to binary, if it was stored in the ddl log. If it was
not stored (long query string), log the following query to binary log:
use `database` ; DROP TRIGGER IF EXISTS `trigger_name`
/* generated by ddl log */;
Other things:
- Added trigger name and DDL_LOG_STATE to drop_trigger()
Trigger name was added to make the interface more consistent and
more general.
- Major rewrite of ddl_log.cc and ddl_log.h
- ddl_log.cc described in the beginning how the recovery works.
- ddl_log.log has unique signature and is dynamic. It's easy to
add more information to the header and other ddl blocks while still
being able to execute old ddl entries.
- IO_SIZE for ddl blocks is now dynamic. Can be changed without affecting
recovery of old logs.
- Code is more modular and is now usable outside of partition handling.
- Renamed log file to dll_recovery.log and added option --log-ddl-recovery
to allow one to specify the path & filename.
- Added ddl_log_entry_phase[], number of phases for each DDL action,
which allowed me to greatly simply set_global_from_ddl_log_entry()
- Changed how strings are stored in log entries, which allows us to
store much more information in a log entry.
- ddl log is now always created at start and deleted on normal shutdown.
This simplices things notable.
- Added probes debug_crash_here() and debug_simulate_error() to simply
crash testing and allow crash after a given number of times a probe
is executed. See comments in debug_sync.cc and rename_table.test for
how this can be used.
- Reverting failed table and view renames is done trough the ddl log.
This ensures that the ddl log is tested also outside of recovery.
- Added helper function 'handler::needs_lower_case_filenames()'
- Extend binary log with Q_XID events. ddl log handling is using this
to check if a ddl log entry was logged to the binary log (if yes,
it will be deleted from the log during ddl_log_close_binlogged_events()
- If a DDL entry fails 3 time, disable it. This is to ensure that if
we have a crash in ddl recovery code the server will not get stuck
in a forever crash-restart-crash loop.
mysqltest.cc changes:
- --die will now replace $variables with their values
- $error will contain the error of the last failed statement
storage engine changes:
- maria_rename() was changed to be more robust against crashes during
rename.
This change removed 68 explict strlen() calls from the code.
The following renames was done to ensure we don't use the old names
when merging code from earlier releases, as using the new variables
for print function could result in crashes:
- charset->csname renamed to charset->cs_name
- charset->name renamed to charset->coll_name
Almost everything where mechanical changes except:
- Changed to use the new Protocol::store(LEX_CSTRING..) when possible
- Changed to use field->store(LEX_CSTRING*, CHARSET_INFO*) when possible
- Changed to use String->append(LEX_CSTRING&) when possible
Other things:
- There where compiler issues with ensuring that all character set names
points to the same string: gcc doesn't allow one to use integer constants
when defining global structures (constant char * pointers works fine).
To get around this, I declared defines for each character set name
length.
- Changed order of class fields to remove dead alignment space.
- Changed bool fields in Item to bit fields.
- Used packed enum's for some fields in common classes
- Removed not used Item::rsize.
- Changed some class variables from uint/int to smaller type int's.
- Ensured that field_index is uint16 in all classes and functions. Fixed
also that we proparly compare with NO_CACHED_FIELD_INDEX when checking
if variable is not set.
- Removed checking of highest bit of unireg_check (has not been used in
a long time)
- Fixed wrong arguments to make_cond_for_table() for join_tab_idx_arg
from false to 0.
One of the result was reducing the size if class Item with ~24 bytes
This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.
The problem was that in a timeout event,
thd->lex->restore_backup_query_tables_list() was called when it should
not have been.
Patch tested with the script in MDEV-25651 (not suitable for mtr)
The bug is that we don't have a a lock on the trigger name, so it is
possible for two threads to try to create the same trigger at the same
time and both thinks that they have succeed.
Same thing can happen with drop trigger or a combinations of create and
drop trigger.
Fixed by adding a mdl lock for the trigger name for the duration of the
create/drop.
Patch tested by Elena
