Re: Optimizing a query - Mailing list pgsql-performance

From James Cloos
Subject Re: Optimizing a query
Date
Msg-id m3psanjuey.fsf@lugabout.jhcloos.org
Whole thread Raw
In response to Re: Optimizing a query  ("Tomeh, Husam" <htomeh@firstam.com>)
Responses Re: Optimizing a query  ("Tomeh, Husam" <htomeh@firstam.com>)
List pgsql-performance
>>>>> "Husam" == Tomeh, Husam <htomeh@firstam.com> writes:

Husam> Have you run vacuum/analyze on the table?

Yes, back when I first noticed how slow it was.
It did not make any difference.

explain analyze says:

,----
| n=# explain analyse  select * from nanpa where npa=775 and nxx=473;
|                                                QUERY PLAN
| --------------------------------------------------------------------------------------------------------
|  Seq Scan on nanpa  (cost=0.00..5344.60 rows=4 width=105) (actual time=371.718..516.816 rows=1 loops=1)
|    Filter: (((npa)::text = '775'::text) AND ((nxx)::text = '473'::text))
|  Total runtime: 516.909 ms
| (3 rows)
`----

vs:

,----
| n=# explain analyse  select * from nanpa where npa=775::char and nxx=473::char;
|                                                       QUERY PLAN

|
----------------------------------------------------------------------------------------------------------------------
|  Index Scan using nanpa_pkey on nanpa  (cost=0.00..4.33 rows=1 width=105) (actual time=64.831..64.831 rows=0 loops=1)
|    Index Cond: ((npa = '7'::bpchar) AND (nxx = '4'::bpchar))
|  Total runtime: 64.927 ms
| (3 rows)
`----

BTW, I forgot to mention I'm at 8.1.4 on that box.

-JimC
--
James Cloos <cloos@jhcloos.com>         OpenPGP: 1024D/ED7DAEA6

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