FILTER_MYSQLBINLOG(1p) User Contributed Perl Documentation FILTER_MYSQLBINLOG(1p)NAME
filter_mysqlbinlog - Trimming ROLLBACK statements and equivalent BINLOG events added by mysqlbinlog. This script is now obsolete.
SYNOPSIS
mysqlbinlog binary_or_relay_log_file | filter_mysqlbinlog
Note that this script is now obsolete and not used by MHA by default.
DESCRIPTION
mysqlbinlog command provided by Oracle implicitly adds ROLLBACK statements and equivalent BINLOG events. But this causes problems when
recovering slave servers. To recover slaves, MHA might need to apply the following binlog events.
1) Relay log events from Relay_Log_Pos to the end of the relay log file
2) Differential relay log events from the latest slave
3) Differential binary log events from the dead master mysqlbinlog command needs to be executed on these files separately. If a
transaction does not end by 1) or 2), implicit ROLLBACK event rolls back the transaction, which will result in inconsistency.
filter_mysqlbinlog is a tool to fix this issue. Note that ROLLBACK statements themselves are added in usual situations. For example, when
you execute 1. BEGIN; 2. Updating transactional tables 3. Updating non-transactional tables 4. ROLLBACK, a ROLLBACK statement is written
to the binary log to rollback transactional queries. This is normal situation so filter_mysqlbinlog must not remove all ROLLBACK events.
Note that this script is now obsolete and not used by MHA by default.
perl v5.14.2 2012-01-08 FILTER_MYSQLBINLOG(1p)
Check Out this Related Man Page
ROLLBACK TO SAVEPOINT(7) SQL Commands ROLLBACK TO SAVEPOINT(7)NAME
ROLLBACK TO SAVEPOINT - roll back to a savepoint
SYNOPSIS
ROLLBACK [ WORK | TRANSACTION ] TO [ SAVEPOINT ] savepoint_name
DESCRIPTION
Roll back all commands that were executed after the savepoint was established. The savepoint remains valid and can be rolled back to again
later, if needed.
ROLLBACK TO SAVEPOINT implicitly destroys all savepoints that were established after the named savepoint.
PARAMETERS
savepoint_name
The savepoint to roll back to.
NOTES
Use RELEASE SAVEPOINT [release_savepoint(7)] to destroy a savepoint without discarding the effects of commands executed after it was estab-
lished.
Specifying a savepoint name that has not been established is an error.
Cursors have somewhat non-transactional behavior with respect to savepoints. Any cursor that is opened inside a savepoint will be closed
when the savepoint is rolled back. If a previously opened cursor is affected by a FETCH command inside a savepoint that is later rolled
back, the cursor position remains at the position that FETCH left it pointing to (that is, FETCH is not rolled back). Closing a cursor is
not undone by rolling back, either. A cursor whose execution causes a transaction to abort is put in a cannot-execute state, so while the
transaction can be restored using ROLLBACK TO SAVEPOINT, the cursor can no longer be used.
EXAMPLES
To undo the effects of the commands executed after my_savepoint was established:
ROLLBACK TO SAVEPOINT my_savepoint;
Cursor positions are not affected by savepoint rollback:
BEGIN;
DECLARE foo CURSOR FOR SELECT 1 UNION SELECT 2;
SAVEPOINT foo;
FETCH 1 FROM foo;
?column?
----------
1
ROLLBACK TO SAVEPOINT foo;
FETCH 1 FROM foo;
?column?
----------
2
COMMIT;
COMPATIBILITY
The SQL standard specifies that the key word SAVEPOINT is mandatory, but PostgreSQL and Oracle allow it to be omitted. SQL allows only
WORK, not TRANSACTION, as a noise word after ROLLBACK. Also, SQL has an optional clause AND [ NO ] CHAIN which is not currently supported
by PostgreSQL. Otherwise, this command conforms to the SQL standard.
SEE ALSO
BEGIN [begin(7)], COMMIT [commit(7)], RELEASE SAVEPOINT [release_savepoint(7)], ROLLBACK [rollback(7)], SAVEPOINT [savepoint(7)]
SQL - Language Statements 2010-05-14 ROLLBACK TO SAVEPOINT(7)