Non-transactional updates that take place inside a transaction present problems
for logging because they are visible to other clients before the transaction
is committed, and they are not rolled back even if the transaction is rolled
back. It is not always possible to log correctly in statement format when both
transactional and non-transactional tables are used in the same transaction.
In the current patch, we ensure that such scenario is completely safe under the
ROW and MIXED modes.
binlog
Mixing transactional (T) and non-transactional (N) tables on behalf of a
transaction may lead to inconsistencies among masters and slaves in STATEMENT
mode. The problem stems from the fact that although modifications done to
non-transactional tables on behalf of a transaction become immediately visible
to other connections they do not immediately get to the binary log and therefore
consistency is broken. Although there may be issues in mixing T and M tables in
STATEMENT mode, there are safe combinations that clients find useful.
In this bug, we fix the following issue. Mixing N and T tables in multi-level
(e.g. a statement that fires a trigger) or multi-table table statements (e.g.
update t1, t2...) were not handled correctly. In such cases, it was not possible
to distinguish when a T table was updated if the sequence of changes was N and T.
In a nutshell, just the flag "modified_non_trans_table" was not enough to reflect
that both a N and T tables were changed. To circumvent this issue, we check if an
engine is registered in the handler's list and changed something which means that
a T table was modified.
Check WL 2687 for a full-fledged patch that will make the use of either the MIXED or
ROW modes completely safe.
mysql-test/suite/binlog/r/binlog_row_mix_innodb_myisam.result:
Truncate statement is wrapped in BEGIN/COMMIT.
mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result:
Truncate statement is wrapped in BEGIN/COMMIT.
