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Re: Help with a very slow select query
Posted by: Richard Buckmaster
Date: February 02, 2011 06:02AM

You really need to use modern join syntax to get the best performance. Sometimes that is all that is needed. Here is your query rewritten:

SELECT count(articulos_en_categorias.id_articulo) as total
FROM articulos
INNER JOIN articulos_en_categorias ON articulos_en_categorias.id_articulo = articulos.id_articulo
WHERE articulos.expirado = '0'
AND articulos.activo = '1'
AND articulos.eliminado = '0'
AND articulos.id_estado_articulo > 2
AND articulos.id_estado_articulo < 5
AND articulos_en_categorias.id_categoria = '125';

Also, if all you are trying to get a count of articles in categories you can do it with a single statement execution. Here is your query that produces a set of id_categoria values along with an associated count. (I have aliased the tables names to make the query easier to read).

SELECT AinC.id_categoria, count(*) as ArtInCat
FROM articulos Art
INNER JOIN articulos_en_categorias AinC ON AinC.id_articulo = Art.id_articulo
WHERE Art.expirado = '0'
AND Art.activo = '1'
AND Art.eliminado = '0'
AND Art.id_estado_articulo > 2
AND Art.id_estado_articulo < 5
GROUP BY AinC.id_categoria;

Finally, you need to make sure there is a non-unique index on articulos_en_categorias.id_categoria

Hope this helps.

Rich.

http://www.rlbuckmaster.com

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Re: Help with a very slow select query
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