Re: Why Stored Procedure is Slower In The Following Case?

From: "A(dot) Kretschmer" <andreas(dot)kretschmer(at)schollglas(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Why Stored Procedure is Slower In The Following Case?
Date: 2010-01-20 07:22:11
Message-ID: 20100120072209.GA21597@a-kretschmer.de
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In response to Yan Cheng Cheok :
> As you can see, their select statement is the same. Except stored
> procedure is having additional 'QUERY'. Does that make the speed
> difference?

No. The problem is, the planner don't know the actual parameters.
Therefore the planner picked out a wrong plan (seq-scan instead of
index-scan). You can avoid this by rewrite your function: use a dynamic
query, use EXECUTE.

Read more:
http://www.postgresql.org/docs/8.4/interactive/plpgsql-control-structures.html
Chapter 38.6.1.2. RETURN NEXT and RETURN QUERY

Andreas
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Andreas Kretschmer
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