On Fri, May 6, 2011 at 5:47 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Wed, Mar 30, 2011 at 8:52 AM, Heikki Linnakangas > <heikki.linnakan...@enterprisedb.com> wrote: >>> Another question: >>> To address the problem in >>> http://archives.postgresql.org/pgsql-hackers/2010-02/msg02097.php >>> , should we just clear the vm before the log of insert/update/delete? >>> This may reduce the performance, is there another solution? >> >> Yeah, that's a straightforward way to fix it. I don't think the performance >> hit will be too bad. But we need to be careful not to hold locks while doing >> I/O, which might require some rearrangement of the code. We might want to do >> a similar dance that we do in vacuum, and call visibilitymap_pin first, then >> lock and update the heap page, and then set the VM bit while holding the >> lock on the heap page. > > Here's an attempt at implementing the necessary gymnastics.
Is there a quick synopsis of why you have to do (sometimes) the pin->lock->unlock->pin->lock mechanic? How come you only can fail to get the pin at most once? merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
