On Tue, 2013-07-02 at 19:34 +0200, Andres Freund wrote: > Well, I still have my doubts that it's a good idea to remove this > knowledge from the page level. And that's not primarily related to > performance. Unfortunately a good part of judging architectural > questions is gut feeling... > The only real argument for the removal I see - removal of one cycle of > dirtying - wouldn't really weigh much if we would combine it with > freezing (which we can do if Robert's forensic freezing patch makes it > in).
I'll have to take a closer look at the relationship between Robert's and Heikki's proposals. I have a gut feeling that the complexity we go through to maintain PD_ALL_VISIBLE is unnecessary and will cause us problems later. If we could combine freezing and marking all-visible, and use WAL for PD_ALL_VISIBLE in a normal fashion, then I'd be content with that. Even better would be if we could eliminate the freeze I/O with Heikki's proposal, and eliminate the PD_ALL_VISIBLE I/O with my patch. But, that's easier said than done. Regards, Jeff Davis -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers