| From: | Andres Freund <andres(at)anarazel(dot)de> |
|---|---|
| To: | Mariel Cherkassky <mariel(dot)cherkassky(at)gmail(dot)com> |
| Cc: | pgsql-admin(at)lists(dot)postgresql(dot)org |
| Subject: | Re: unclear behavior xmax/xmin |
| Date: | 2018-11-18 20:34:28 |
| Message-ID: | 20181118203428.6oyyhksg46i5mzsv@alap3.anarazel.de |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-admin |
Hi,
(Please don't top quote on this list, we do inline responses here)
On 2018-11-18 22:28:24 +0200, Mariel Cherkassky wrote:
> Just exploring the database and trying to understand the logic behind
> things :)
> So after a rollback why the xmax isnt changed back to 0 ? Seems like it
> should be set again to 0.
Because that'd mean that a rollback would have to re-process every page
that the transaction has touched, which'd be pretty expensive for large
transactions. And we couldn't rely on it being 0, because there's also
the case that the machine crashed.
Greetings,
Andres Freund
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Häfliger Guido | 2018-11-19 09:36:02 | logging aql queries only one table or tables of one scheme |
| Previous Message | Mariel Cherkassky | 2018-11-18 20:28:24 | Re: unclear behavior xmax/xmin |