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shared intended exclusive locks
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nikosv
Jul 18, 2012, 6:57:29 AM7/18/12
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Is there a way to indicate shared intended exclusive locks on page/row level (update locks) like locking hints or Select For Update ? I am not on MVCC and I'd would use it to avoid deadlocks in certain situations
Ingres Forums
Jul 18, 2012, 7:32:56 AM7/18/12
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If you're not using MVCC then pessimistic locking is all you have to
work with. In which case all you can do is SET LOCKMODE SESSION WHERE
READLOCK=EXCLUSIVE.
That'll be highly disruptive if you don't immediately revert to
READLOCK=SYSTEM as soon as you no longer need it.
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rhann
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nikosv
Jul 18, 2012, 9:56:02 AM7/18/12
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>SET LOCKMODE SESSION WHERE READLOCK=EXCLUSIVE.
does it take immediate effect or is it activated on the first select ?
Ingres Forums
Jul 18, 2012, 10:32:23 AM7/18/12
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It has to be issued outside the scope of a transaction (i.e. following a
commit or a rollback) so for practical purposes it takes effect on the
first query after you set it.
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