From: Vadim Mikheev <vadim@krs.ru>
To: Remigiusz Sokolowski <rems@gdansk.sprint.pl>
Cc: pgsql-sql@postgreSQL.org
Subject: Re: [SQL] indexes
Date: Mon, 31 May 1999 16:50:50 +0800
Message-ID: <37524D6A.6B8B50E@krs.ru> (raw)
References: <Pine.GS4.4.02A.9905311027530.26326-100000@netra.gdansk.sprint.pl>
Remigiusz Sokolowski wrote:
>
> Hi!
> I try to optimize following query
> SELECT DISTINCT e1.name_ent AS nazwa_grupy
> FROM ent e1, binds b1, ent e2
> WHERE e1.id_ent=b1.id_parent AND b1.id_child=e2.id_ent AND b1.id_links=0
^^^^^^^^^^^^^
> AND e2.name_ent='SERWIS';
>
> Is it possible to get better results? From explain notes it looks, that
> engine uses indexes on ent table, but I can't constrain it to use any
> index on binds table - this causes main problem.
> Or may be query should look in other way?
>
...
> Table = binds2_idx
> +--------------------+----------------------------------+------+
> |Field | Type |Length|
> +--------------------+----------------------------------+------+
> | id_parent | int4 |4 |
> | id_child | int4 |4 |
> | id_links | int4 |4 |
> +--------------------+----------------------------------+------+
Try to create index on binds (id_links, id_parent, id_child)
Vadim
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To: pgsql-sql@postgresql.org
Cc: vadim@krs.ru, rems@gdansk.sprint.pl
Subject: Re: [SQL] indexes
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