Re: INSERT...ON DUPLICATE KEY LOCK FOR UPDATE - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: INSERT...ON DUPLICATE KEY LOCK FOR UPDATE
Date
Msg-id CAM3SWZSJ_Oc5VLfXqAtUafNTzQKrfsR5RTWVKfvOfZkFCxCrig@mail.gmail.com
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In response to Re: INSERT...ON DUPLICATE KEY LOCK FOR UPDATE  (Peter Geoghegan <pg@heroku.com>)
List pgsql-hackers
On Sat, Sep 21, 2013 at 7:22 PM, Peter Geoghegan <pg@heroku.com> wrote:
> So because this isn't a tuple-level lock - it's really a value-level
> lock - LockTuple() is not called by the btree code at all, and so
> arbitration of who gets the lock is, as I've said, essentially
> undefined.

Addendum: It isn't even a value-level lock, because the buffer locks
are of course released before the XactLockTableWait() call. It's a
simple attempt to acquire a shared lock on an xid.


-- 
Peter Geoghegan



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