Re: Stored procedure slower than sql?

["Jim C. Nasby" <jim(at)nasby(dot)net>]

The planner has no idea what $1 and $2 are when it plans the query, so
that could easily explain why the performance is different. You can
prepare statements in psql (at least in 8.1), which would be a good way
to verify that theory (compare EXPLAIN for prepared vs. non).

On Thu, Oct 26, 2006 at 09:21:37AM -0700, Matthew Peters wrote:
> Parameterized.
> 
> IE (very simplified)
> 
> CREATE OR REPLACE FUNCTION my_function(IN param1 BIGINT, IN param2
> INTEGER)
> RETURNS my_type
> SECURITY DEFINER
> AS
> $$
> 	/* my_type = (a,b,c) */
> 	Select a,b,c
> 	FROM my_table
> 	WHERE indexed_column = $1
> 	AND partition_constraint_column = $2;
> $$
> LANGUAGE SQL;
> 
> 
> 
> 
> Matthew A. Peters
> Sr. Software Engineer, Haydrian Corp.
> matthew(at)haydrian(dot)com
> (mobile) 425-941-6566
>  Haydrian Corp.
> -----Original Message-----
> From: Tom Lane [mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us] 
> Sent: Thursday, October 26, 2006 9:15 AM
> To: Matthew Peters
> Cc: pgsql-performance(at)postgresql(dot)org
> Subject: Re: [PERFORM] Stored procedure slower than sql? 
> Importance: High
> 
> "Matthew Peters" <matthew(at)haydrian(dot)com> writes:
> > How can a stored procedure containing a single query not implement the
> > same execution plan (assumption based on the dramatic performance
> > difference) that an identical ad-hoc query generates?
> 
> Parameterized vs non parameterized query?
> 
> 			regards, tom lane
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 1: if posting/reading through Usenet, please send an appropriate
>        subscribe-nomail command to majordomo(at)postgresql(dot)org so that your
>        message can get through to the mailing list cleanly
> 

-- 
Jim Nasby                                            jim(at)nasby(dot)net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)