On Mon, Jun 25, 2012 at 01:50:54PM -0500, Kevin Grittner wrote: > Andres Freund <and...@2ndquadrant.com> wrote: > > > I am not sure were going to get all that into 9.3. > > Sure, that was more related to why I was questioning how much these > use cases even *could* integrate -- whether it even paid to > *consider* these use cases at this point. Responses from Robert and > you have pretty much convinced me that I was being overly > pessimistic on that. > > One fine point regarding before and after images -- if a value > doesn't change in an UPDATE, there's no reason to include it in both > the BEFORE and AFTER tuple images, as long as we have the null > column bitmaps -- or some other way of distinguishing unchanged from > NULL. (This could be especially important when the unchanged column > was a 50 MB bytea.)
How about two bitmaps: one telling which columns are actually there, the other with NULLs? Cheers, David. -- David Fetter <da...@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fet...@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
