Обсуждение: Help with performance

Hi!

I have 2 tables

\d table1

     Column     |           Type
----------------+--------------------------
 id_entry       | integer
 created        | timestamp with time zone
 title          | character varying(64)
 description    | text

Primary key: table1_pk
Index "table1_pk"
  Column  |  Type
----------+---------
 id_entry | integer
unique btree (primary key)

\d table2
   Column    |         Type
-------------+-----------------------
 id_category | character varying(64)
 id_entry    | character varying(64)
Primary key: table2_pk

\d table2_pk
   Column    |         Type
-------------+-----------------------
 id_category | character varying(64)
 id_entry    | character varying(64)
unique btree (primary key)


Not i have  query like this

select d.title from table1 d, table2 c where c.id_category='09' and d.id_entry=c.id_entry;

This is query plan


--
lp,
 Uros                          mailto:uros.gruber@sir-mag.com

On Wed, Apr 24, 2002 at 10:49:12PM +0200, Uros Gruber wrote:

First you have:
>  id_entry       | integer

Then you have:
>  id_entry    | character varying(64)

> Not i have  query like this
>
> select d.title from table1 d, table2 c where c.id_category='09' and d.id_entry=c.id_entry;

With those types so different, it makes it difficult to use indexes in
certain ways. Perhaps an explicit cast?

--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Canada, Mexico, and Australia form the Axis of Nations That
> Are Actually Quite Nice But Secretly Have Nasty Thoughts About America