Re: pg_upgrade and statistics - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: pg_upgrade and statistics
Date
Msg-id 1331649152-sup-3424@alvh.no-ip.org
Whole thread Raw
In response to Re: pg_upgrade and statistics  (Bruce Momjian <bruce@momjian.us>)
Responses Re: pg_upgrade and statistics  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers
Excerpts from Bruce Momjian's message of mar mar 13 11:14:43 -0300 2012:
> On Tue, Mar 13, 2012 at 12:33:09AM -0700, Daniel Farina wrote:
> > On Mon, Mar 12, 2012 at 8:10 PM, Bruce Momjian <bruce@momjian.us> wrote:
> > > To answer your specific question, I think clearing the last analyzed
> > > fields should cause autovacuum to run on analyze those tables.  What I
> > > don't know is whether not clearing the last vacuum datetime will cause
> > > the table not to be analyzed.
> >
> > Thank you very much for this reference.  I will look into it.
>
> I assume a missing last_analyze would trigger an auto-analyze,

You're wrong.  Autovacuum does not consider time, only dead/live tuple
counts.  The formulas it uses are in the autovacuum docs; some details
(such as the fact that it skips tables that do not have stat entries)
might be missing.

--
Álvaro Herrera <alvherre@commandprompt.com>
The PostgreSQL Company - Command Prompt, Inc.
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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