Subject: Re: Using Temporary Tables in postgres functions
From: Mario Splivalo <mario.splivalo@mobart.hr>
Reply-To: mario.splivalo@mobart.hr
To: pgsql-sql@postgresql.org
In-Reply-To: <20070125080212.M1153@megazone.bigpanda.com>
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	<20070125080212.M1153@megazone.bigpanda.com>
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Organization: Mob-Art d.o.o.
Date: Fri, 26 Jan 2007 11:46:37 +0100
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On Thu, 2007-01-25 at 08:03 -0800, Stephan Szabo wrote:
> On Thu, 25 Jan 2007, Mario Splivalo wrote:
> 
> > When I try to use TEMPORARY TABLE within postgres functions (using 'sql'
> > as a function language), I can't because postgres can't find that
> > temporary table. Consider this example:
> >
> > CREATE FUNCTION func1() RETURNS SETOF v_messages_full AS $BODY$
> > CREATE TEMPORARY TABLE tmpTbl
> > AS
> > SELECT
> > 	message_id
> > FROM
> > 	cached_messages
> > WHERE
> > 	billing_status = 2;
> >
> >
> > UPDATE cached_messages SET billing_status = 1 WHERE message_id IN
> > (SELECT message_id FROM tmpTbl);
> >
> > SELECT
> > 	*
> > FROM
> > 	v_messages_full
> > WHERE
> > 	message_id IN (SELECT message_id FROM tmpTbl);
> > $BODY$ LANGUAGE 'sql' VOLATILE SECURITY DEFINER;
> 
> It seems like the sql function checker is unhappy with the above. Does it
> actually work if you turn off the check_function_bodies configuration
> variable, create the function and then call it?

Yes, when I do 'set check_function_bodies to false;' then I can create
the function but I'm unable to execute it:

testdb1=# select * from func1();
ERROR:  relation "tmptbl" does not exist
CONTEXT:  SQL function "func1" during startup

Bummer. In the end I wrote the function using plpgsql. Now, is there any
performance impact on using plpgsql instead of sql in simple scenarios
as in func1() example? I guess there should be some, as minimas as it
can be, but have no way of actualy knowing that.

	Mike