| From: | Greg Smith <greg(at)2ndQuadrant(dot)com> |
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: auto vacuum, not working? |
| Date: | 2012-01-15 12:09:50 |
| Message-ID: | 4F12C20E.7080400@2ndQuadrant.com |
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| Lists: | pgsql-performance |
On 01/13/2012 07:08 AM, Anibal David Acosta wrote:
>
> How can I release the space used by deleted rows? Without block the table.
>
>
The database can only reduce the size tables by returning space to the
operating system in one situation: there is free space at the very end
of the table. In that case, if it's possible to get a brief exclusive
lock on the table, it can shrink in size.
There are some programs available that reorganize table for goals like
this, without having any long-lasting locks on the tables. pg_reorg is
the most popular example: http://pgfoundry.org/projects/reorg/
--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com
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