Re: General performance problem!

olivier HARO wrote:

> Hello,
>
> I have a dedicated server for my posgresql database :
>
> P4 2.4 GHZ
> HDD IDE 7200 rpm
> 512 DDR 2700
>
> I have a problem whith one table of my database :
>
> CREATE SEQUENCE "base_aveugle_seq" START 1;
> CREATE TABLE "base_aveugle" (
> "record_id" integer DEFAULT nextval('"base_aveugle_seq"'::text) NOT NULL,
> "dunsnumber" integer NOT NULL,
> "cp" text NOT NULL,
> "tel" text NOT NULL,
> "fax" text NOT NULL,
> "naf" text NOT NULL,
> "siege/ets" text NOT NULL,
> "effectif" integer NOT NULL,
> "ca" integer NOT NULL,
> Constraint "base_aveugle_pkey" Primary Key ("record_id")
> );
> CREATE INDEX base_aveugle_dunsnumber_key ON base_aveugle USING btree
> (dunsnumber);
> CREATE INDEX base_aveugle_cp_key ON base_aveugle USING btree (cp);
> CREATE INDEX base_aveugle_naf_key ON base_aveugle USING btree (naf);
> CREATE INDEX base_aveugle_effectif_key ON base_aveugle USING btree
> (effectif);
>
>
> This table contains 5 000 000 records
>
> I have a PHP application which often makes queries on this table
> (especially on the "cp","naf","effectif" fields)
>
> Querries are like :
> select (distint cp) from base_aveugle where cp='201A' and effectif
> between 1 and 150
> select (*) from base_aveugle where naf in ('721A','213F','421K')
> and cp in ('54210','21459','201A') and effectif < 150
>
> I think it is possible to optimize the performance of this queries
> before changing the hardware (I now I will...) but I don't know how,
> even after having read lot of things about postgresql ...

Show us a explain analyze for that queries.

Regards
Gaetano Mendola