Re: Why age (datfrozenxid) in postgres becomes 1073742202 not zero after each vacuum of database.

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Brahma Prakash Tiwari <brahma(dot)tiwari(at)inventum(dot)cc>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Why age (datfrozenxid) in postgres becomes 1073742202 not zero after each vacuum of database.
Date: 2009-11-13 21:05:38
Message-ID: 603c8f070911131305t1fc446fcw13df71b67da9093@mail.gmail.com
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On Thu, Nov 12, 2009 at 3:18 AM, Brahma Prakash Tiwari
<brahma(dot)tiwari(at)inventum(dot)cc> wrote:
> Hi all
>
> Why age (datfrozenxid) in postgres becomes 1073742202 not zero after vacuum
> of database.
>
> Thanks in advance

I think you're misunderstanding the meaning of the column. As the
fine manual explains:

"Similarly, the datfrozenxid column of a database's pg_database row is
a lower bound on the normal XIDs appearing in that database — it is
just the minimum of the per-table relfrozenxid values within the
database."

http://www.postgresql.org/docs/current/static/routine-vacuuming.html

...Robert

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