when there are no up-to-date system tables to support it:
- initialize the scheduler before reporting "Ready for connections".
This ensures that warnings, if any, are printed before "Ready for
connections", and this message is not mangled.
- do not abort the scheduler if there are no system tables
- check the tables once at start up, remember the status and disable
the scheduler if the tables are not up to date.
If one attempts to use the scheduler with bad tables,
issue an error message.
- clean up the behaviour of the module under LOCK TABLES and pre-locking
mode
- make sure implicit commit of Events DDL works as expected.
- add more tests
Collateral clean ups in the events code.
This patch fixes Bug#23631 Events: SHOW VARIABLES doesn't work
when mysql.event is damaged
BUG#26429: SHOW CREATE EVENT is incorrect for an event that
STARTS NOW()
BUG#26431: Impossible to re-create an event from backup if its
STARTS clause is in the past
WL#3698: Events: execution in local time zone
The problem was that local times specified by the user in AT, STARTS
and ENDS of CREATE EVENT/ALTER EVENT statement were converted to UTC,
and the original time zone was forgotten. This way, event scheduler
couldn't honor Daylight Saving Time shifts, and times shown to the
user were also in UTC. Additionally, CREATE EVENT didn't allow times
in the past, thus preventing straightforward event restoration from
old backups.
This patch reworks event scheduler time computations, performing them
in the time zone associated with the event. Also it allows times to
be in the past.
The patch adds time_zone column to mysql.event table.
NOTE: The patch is almost final, but the bug#9953 should be pushed
first.
