temp table
This patch introduces two key changes in the replication's behavior.
Firstly, it reverts part of BUG#51894 which puts any update to temporary tables
into the trx-cache. Now, updates to temporary tables are handled according to
the type of their engines as a regular table.
Secondly, an unsafe mixed statement, (i.e. a statement that access transactional
table as well non-transactional or temporary table, and writes to any of them),
are written into the trx-cache in order to minimize errors in the execution when
the statement logging format is in use.
Such changes has a direct impact on which statements are classified as unsafe
statements and thus part of BUG#53259 is reverted.
transaction
BUG#52616 Temp table prevents switch binlog format from STATEMENT to ROW
Before the WL#2687 and BUG#46364, every non-transactional change that happened
after a transactional change was written to trx-cache and flushed upon
committing the transaction. WL#2687 and BUG#46364 changed this behavior and
non-transactional changes are now written to the binary log upon committing
the statement.
A binary log event is identified as transactional or non-transactional through
a flag in the Log_event which is set taking into account the underlie storage
engine on what it is stems from. In the current bug, this flag was not being
set properly when the DROP TEMPORARY TABLE was executed.
However, while fixing this bug we figured out that changes to temporary tables
should be always written to the trx-cache if there is an on-going transaction.
Otherwise, binlog events in the reversed order would be produced.
Regarding concurrency, keeping changes to temporary tables in the trx-cache is
also safe as temporary tables are only visible to the owner connection.
In this patch, we classify the following statements as unsafe:
1 - INSERT INTO t_myisam SELECT * FROM t_myisam_temp
2 - INSERT INTO t_myisam_temp SELECT * FROM t_myisam
3 - CREATE TEMPORARY TABLE t_myisam_temp SELECT * FROM t_myisam
On the other hand, the following statements are classified as safe:
1 - INSERT INTO t_innodb SELECT * FROM t_myisam_temp
2 - INSERT INTO t_myisam_temp SELECT * FROM t_innodb
The patch also guarantees that transactions that have a DROP TEMPORARY are
always written to the binary log regardless of the mode and the outcome:
commit or rollback. In particular, the DROP TEMPORARY is extended with the
IF EXISTS clause when the current statement logging format is set to row.
Finally, the patch allows to switch from STATEMENT to MIXED/ROW when there
are temporary tables but the contrary is not possible.
The test case added in previous patch missed a RESET MASTER on
test start up. Without it, showing binary log contents can
sometimes show spurious entries from previously executed tests,
ultimately causing test failure - result mismatch.
The test file was added in:
revid:luis.soares@sun.com-20100224190153-k0bpdx9abe88uoo2
This patch also moves the test case into binlog_innodb_row.test
file. This way we avoid having yet another test file,
binlog_row_innodb_truncate.test, whose only purpose is to host
one test case. This had been actually suggested during original
patch review, but somehow the binlog_innodb_row was missed when
searching for a file to host the test case.
A transaction could result in having an extra event after a query that
errored e.g because of a dup key. Such a query is rolled back in
innodb, as specified, but has not been in binlog.
It appeares that the binlog engine did not always register for a query
(statement) because the previous query had not reset at its statement
commit time. Because of that fact there was no roll-back to the
trx_data->before_stmt_pos position and a the pending event of the
errorred query could become flushed to the binlog file.
Fixed with deploying the reset of trx_data->before_stmt_pos at the end
of the query processing.
