Re: pg_upgrade and statistics - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: pg_upgrade and statistics
Date
Msg-id 20120313144926.GK10441@momjian.us
Whole thread Raw
In response to Re: pg_upgrade and statistics  (Alvaro Herrera <alvherre@commandprompt.com>)
Responses Re: pg_upgrade and statistics
List pgsql-hackers
On Tue, Mar 13, 2012 at 11:34:16AM -0300, Alvaro Herrera wrote:
> 
> 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.

Oh, yes.  Thank you for the correction;  not sure what I was thinking.

How would they trigger an autovacuum then?

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +


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