| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Jan Wieck <JanWieck(at)Yahoo(dot)com> |
| Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Russell Smith <mr-russ(at)pws(dot)com(dot)au>, Josh Berkus <josh(at)agliodbs(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Idea for getting rid of VACUUM FREEZE on cold pages |
| Date: | 2010-06-10 19:16:38 |
| Message-ID: | 20828.1276197398@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Jan Wieck <JanWieck(at)Yahoo(dot)com> writes:
> Depends. Specifically on transaction profiles and how long the blocks
> linger around before being written. If you can set the all visible bit
> by the time, the page is written the first time, what bit including the
> is-frozen one cannot be set at that time too?
All-visible and is-frozen would be the same bit ...
> And even if some cases still required another page write because those
> frozen bits cannot be set on first write, this seems to be a win-win. We
> would get rid of the FrozenXid completely and shift to a bit, so we can
> effectively have a min_ freeze_age of zero while keeping the xid's forever.
Right. I don't see any downside, other than eating another status bit
per tuple, which we can afford.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Alvaro Herrera | 2010-06-10 19:23:47 | Re: Error with GIT Repository |
| Previous Message | Jan Wieck | 2010-06-10 19:04:02 | Re: Idea for getting rid of VACUUM FREEZE on cold pages |