Re: pg_upgrade and statistics

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(at)momjian(dot)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.

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Álvaro Herrera <alvherre(at)commandprompt(dot)com>
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