| From: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> |
|---|---|
| To: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
| Cc: | maciek(at)heroku(dot)com, "pgsql-bugs(at)postgresql(dot)org" <pgsql-bugs(at)postgresql(dot)org> |
| Subject: | Re: BUG #13002: VACUUM to prevent wraparound blocks TRUNCATE |
| Date: | 2015-04-08 19:45:47 |
| Message-ID: | 20150408194547.GW4369@alvh.no-ip.org |
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| Thread: | |
| Lists: | pgsql-bugs |
David G. Johnston wrote:
> Related question: does a truncated table effectively reset its wraparound
> counter back to zero?
Yes, the relfrozenxid is set to RecentXmin (see ExecuteTruncate). Not
quite zero age but unless you have really old transactions around,
should be close enough.
> If the table in question is being truncated regularly it doesn't seem like
> this situation should arise.
Correct.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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