On 2013-10-01 07:41:46 -0700, Kevin Grittner wrote:
> Andres Freund <andres@2ndquadrant.com> wrote:
>
> > A better solution probably is to promote tuple-level locks if
> > they exist to a relation level one upon freezing I guess?
>
> It would be sufficient to promote the tuple lock to a page lock.
> It would be pretty easy to add a function to predicate.c which
> would accept a Relation and HeapTuple, check for a predicate lock
> for the tuple, and add a page lock if found (which will
> automatically clear the tuple lock). This new function would be
> called when a tuple was chosen for freezing. Since freezing always
> causes WAL-logging and disk I/O, the cost of a couple hash table
> operations should not be noticeable.
Yea, not sure why I was thinking of table level locks.
> This seems like a bug fix which should be back-patched to 9.1, yes?
Yes.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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