Bruce Momjian wrote: > Pavan Deolasee wrote: >> On Fri, Feb 26, 2010 at 8:19 AM, Bruce Momjian <br...@momjian.us> wrote: >> >>> Whatever happened to this? It was in the first 9.0 commitfest but was >>> returned with feedback but never updated: >>> >>> >> Though Alex did some useful tests and review, and in fact confirmed that the >> VACUUM time dropped from 16494 msec to 366 msec, I somehow kept waiting for >> Heikki's decision on the general direction of the patch and lost interest in >> between. If we are still interested in this, I can work out a patch and >> submit for next release if not this. > > OK, TODO added: > > Have single-page pruning update the visibility map > * https://commitfest.postgresql.org/action/patch_view?id=75 > > Hopefully Heikki can comment on this.
I think I was worried about the possible performance impact of having to clear the bit in visibility map again. If you're frequently updating a tuple so that HOT and page pruning is helping you, setting the bit in visibility map seems counter-productive; it's going to be cleared soon again by another UPDATE. That's just a hunch, though. Maybe the overhead is negligible. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
