From: "Sabin Coanda" <sabin.coanda@deuromedia.ro>
Subject: low performance on functions returning setof record
Date: Thu, 9 Oct 2008 17:47:30 +0300
Organization: Hub.Org Networking Services
Lines: 24
Message-ID: <gcl5hg$2kq8$1@news.hub.org>
To: pgsql-performance@postgresql.org

Hi there,

I use different functions returning setof record, and they are working well. 
The problem is the performance when I use those functions in joins, for 
instance:

        SELECT *
        FROM "Table1" t1
                JOIN "Function1"( a1, a2, ... aN ) AS f1( ColA int4, ColB 
varchar, ... )
                        ON t1.ColX = f1.ColA

The problem is I'm not able to make indexes on the function, even inside I 
have just another select statement from different permanent tables, with 
some where clauses depending on the function arguments.

Do you know a way to build such a function, returning something I can join 
in an outer select statement like above, using indexes or another way to run 
it faster ?

TIA,
Sabin