Re: autoanalyze criteria

Stefan Andreatta <s.andreatta@xxxxxxxxxxx> · Mon, 25 Feb 2013 07:23:40 +0100



    On 02/24/2013 12:52 PM, Alban Hertroys wrote:

    
        On Feb 23, 2013, at 14:11, Stefan Andreatta <s.andreatta@xxxxxxxxxxx>
          wrote:
        

          And we are still missing
            a number for rows updated since the last analyse.

          
      In MVCC an update is an insert + delete, so you already got
        those numbers.
      

    Good point. But because they are an update and a delete, they cancel
    each other out and do not show up in pg_stat_user_tables.n_live_tup
    - and that's the only value for which we have a reference value from
    the time of the last analyze (pg_class.reltuples).

    
    On the other hand, I might again miss something out. I would be most
    happy if anybody could come up with a query to estimate autoanalyze
    trigger conditions from the values we have available now.

    
    Stefan