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Venkatesh Duggirala authored
IN TIME RECOVERY FAILURE ON SLAVES Problem: DROP TEMP TABLE IF EXISTS commands can cause point in time recovery (re-applying binlog) failures. Analyses: In RBR, 'DROP TEMPORARY TABLE' commands are always binlogged by adding 'IF EXISTS' clauses. Also, the slave SQL thread will not check replicate.* filter rules for "DROP TEMPORARY TABLE IF EXISTS" queries. If log-slave-updates is enabled on slave, these queries will be binlogged in the format of "USE `db`; DROP TEMPORARY TABLE IF EXISTS `t1`;" irrespective of filtering rules and irrespective of the `db` existence. When users try to recover slave from it's own binlog, use `db` command might fail if `db` is not present on slave. Fix: At the time of writing the 'DROP TEMPORARY TABLE IF EXISTS' query into the binlog, 'use `db`' will not be present and the table name in the query will be a fully qualified table name. Eg: 'USE `db`; DROP TEMPORARY TABLE IF EXISTS `t1`;' will be logged as 'DROP TEMPORARY TABLE IF EXISTS `db`.`t1`;'.
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