Re: Efficiency of timestamps

Stephan Szabo wrote:
>
>
> I think you might get better results with some kind of multi-column index.
> It's using the index to avoid a sort it looks like, but it's not helping
> to find the conditions. I can't remember the correct ordering, but maybe
> (posttimestamp, realmname, postidnumber).  Having separate indexes on the
> fields won't help currently since only one index will get chosen for the
> scan.  Also, what does explain analyze show?
>

Hope that shed's light on the matter.

  Limit  (cost=0.00..260237.32 rows=100 width=48) (actual
time=68810.26..68820.83 rows=55 loops=1)
    ->  Index Scan using pkpost on post  (cost=0.00..3020594.00
rows=1161 width=48) (actual time=68810.25..68820.72 rows=55 loops=1)
          Filter: ((posttimestamp > (('now'::text)::timestamp(6) without
time zone - '00:10'::interval)) AND (realmname = 'Amalgam'::character
varying) AND ((postto = 'all'::character varying) OR (postto =
'root'::character varying)) AND ((NOT (subplan)) OR (puppeteerlogin IS
NULL)) AND ((NOT (subplan)) OR (puppetname IS NULL)))
          SubPlan
            ->  Index Scan using pkpuppetignore on puppetignore
(cost=0.00..13.31 rows=1 width=10) (actual time=0.02..0.02 rows=0 loops=55)
                  Index Cond: (puppeteerlogin = 'root'::character varying)
                  Filter: ((puppetignore = 'global'::character varying)
AND (puppetlogin = $0))
            ->  Index Scan using pkpuppetignore on puppetignore
(cost=0.00..5.84 rows=1 width=15) (actual time=0.01..0.01 rows=0 loops=55)
                  Index Cond: ((puppeteerlogin = 'root'::character
varying) AND (puppetname = $1))
                  Filter: (puppetignore = 'single'::character varying)
  Total runtime: 68821.11 msec

--
    Martin Foster
    Creator/Designer Ethereal Realms
    martin@ethereal-realms.org