mysqldump --skip-events --all-databases dumped data of the mysqld.event table,
and during the restoration from this dump events were created in spite
of the --skip-events option.
The mysqldump client has been modified to ignore mysql.event table data
in case of --skip-events options.
DELETE FROM ... USING ... statements with the following type of
ambiguous aliasing gave unexpected results:
DELETE FROM t1 AS alias USING t1, t2 AS alias WHERE t1.a = alias.a;
This query would leave table t1 intact but delete rows from t2.
Fixed by changing DELETE FROM ... USING syntax so that only alias
references (as opposed to alias declarations) may be used in FROM.
When dumping database from a 4.x server, the mysqldump client
inserted a delimiter sign inside special commentaries of the form:
/*!... CREATE DATABASE IF NOT EXISTS ... ;*/
During restoration that dump file was splitten by delimiter signs on
the client side, and the rest of some commentary strings was prepended
to following statements.
The 4x_server_emul test case option has been added for use with the
DBUG_EXECUTE_IF debugging macro. This option affects debug server
builds only to emulate particular behavior of a 4.x server for
the mysqldump client testing. Non-debugging builds are not affected.
and strategy (explain)
The fix for WL3527 adds tests that test if the index usage hints
combinations don't cause syntax errors.
The EXPLAIN for one of these tests can be affected by the size of the
rowid on the disk (affected by the presence of large file support).
Fixed to avoid the platform dependent test result by removing the
irrelevant columns from the EXPLAIN result.
The optimization that uses a unique index to remove GROUP BY did not
ensure that the index was actually used, thus violating the ORDER BY
that is implied by GROUP BY.
Fixed by replacing GROUP BY with ORDER BY if the GROUP BY clause contains
a unique index over non-nullable field(s). In case GROUP BY ... ORDER BY
null is used, GROUP BY is simply removed.
Currently the Last_query_cost session status variable shows
only the cost of a single flat subselect. For complex queries
(with subselects or unions etc) Last_query_cost is not valid
as it was showing the cost for the last optimized subselect.
Fixed by reseting to zero Last_query_cost when the complete
cost of the query cannot be determined.
Last_query_cost will be non-zero only for single flat queries.
In the ha_partition::position() we didn't calculate the number
of the partition of the record. We used m_last_part value instead,
relying on that it is set in other place like previous call of a method
like ::write_row(). In replication we don't call any of these befor
position(). Delete_rows_log_event::do_exec_row calls find_and_fetch_row.
In case of InnoDB-based PARTITION table, we have HA_PRIMARY_KEY_REQUIRED_FOR_POSITION
enabled, so use position() / rnd_pos() calls to fetch the record.
Fixed by adding partition_id calculation to the ha_partition::position()
Although the query cache doesn't support retrieval of statements containing
column level access control, it was still possible to cache such statements
thus wasting memory.
This patch extends the access control check on the target tables to avoid
caching a statement with column level restrictions.
Views are excepted and can be cached but only retrieved by super user account.