Обсуждение: AW: indexes and big tables

> netacc=> EXPLAIN (SELECT SUM(counterfrom) AS from, 
> SUM(counterto) AS to,
> floor((985098900 - date_part('epoch', counterstamp)) / 300) 
> AS sequence
> FROM counters WHERE line='absolonll' AND date_part('epoch', 
> ) counterstamp > 984978900 GROUP BY sequence, line) ...

I would guess the problem is the restriction on counterstamp, because 
written like that, it probably can't use the index.

try something where you avoid the use of the date_part function e.g.:AND counterstamp > '2001-07-26 00:00:00.0'

Andreas

> I would guess the problem is the restriction on counterstamp, because
> written like that, it probably can't use the index.
>
> try something where you avoid the use of the date_part function e.g.:
>     AND counterstamp > '2001-07-26 00:00:00.0'
 I will try it, but it use the index when there is a few amount of rows.
When I insert a lot of rows like me (in milions), index isn't used. I don't
know the number of rows which makes border between using and don't using
index and I can discover it if you want. Going to try your suggestions ...

Best regards, Robert

--   _ |-|  __      Robert Vojta <vojta-at-ipex.cz>          -= Oo.oO =- |=| [Ll]     IPEX, s.r.o. "^" ====`o