Re: planner question..

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От Stephan Szabo
Тема Re: planner question..
Дата
Msg-id 20030417071102.V87131-100000@megazone23.bigpanda.com
обсуждение исходный текст
Ответ на Re: planner question..  (Rajesh Kumar Mallah <mallah@trade-india.com>)
Ответы Re: planner question..  (Rajesh Kumar Mallah <mallah@trade-india.com>)
Список pgsql-sql
On Thu, 17 Apr 2003, Rajesh Kumar Mallah wrote:

> I think there shud be more documentation on
> understanding EXPLAIN (ANALYZE) output.
> once i found an webpage but lost it.

I believe there's one inside the docs on performance or optimization.

>
> where do u see its expecting 5000 not 100000?

> > > | Aggregate  (cost=23982.58..23982.58 rows=1 width=0) (actual
> > > | time=22872.97..22872.97 rows=1 loops=1)                          | ->
> > > | Seq Scan on profile_master  (cost=0.00..23970.40 rows=4871 width=0)
> > > | (actual time=328.44..22730.69 rows=102090 loops=1) |

In the Seq Scan line, it's got rows=4871.  That's the number it thinks are
going to match the filter/index condition.



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