Re: vacuum full, why multiple times ? - Mailing list pgsql-performance

From Richard Huxton
Subject Re: vacuum full, why multiple times ?
Date
Msg-id 422EEC49.7080202@archonet.com
Whole thread Raw
In response to Re: vacuum full, why multiple times ?  (Gaetano Mendola <mendola@bigfoot.com>)
Responses Re: vacuum full, why multiple times ?  (Gaetano Mendola <mendola@bigfoot.com>)
List pgsql-performance
Gaetano Mendola wrote:
>
> # vacuum full verbose url;
> INFO:  vacuuming "public.url"
> INFO:  "url": found 74 removable, 21266 nonremovable row versions in 8550 pages
> DETAIL:  2 dead row versions cannot be removed yet.
> [SNIP]
> INFO:  "url": moved 11 row versions, truncated 8550 to 8504 pages
>
>
> and in the next run:
>
>
> # vacuum full verbose url;
> INFO:  vacuuming "public.url"
> INFO:  "url": found 13 removable, 21264 nonremovable row versions in 8504 pages
> DETAIL:  0 dead row versions cannot be removed yet.
> [SNIP]
> INFO:  "url": moved 5666 row versions, truncated 8504 to 621 pages

If page number 8549 was the one being held, I don't think vacuum can
truncate the file. The empty space can be re-used, but the rows can't be
moved to a lower page while a transaction is using them.

--
   Richard Huxton
   Archonet Ltd

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