Re: function performance vs in-line sql - Mailing list pgsql-performance

From Heikki Linnakangas
Subject Re: function performance vs in-line sql
Date
Msg-id 45F04D62.8090302@enterprisedb.com
Whole thread Raw
In response to function performance vs in-line sql  ("Schwarz, Karl" <Karl.Schwarz@ngc.com>)
List pgsql-performance
Schwarz, Karl wrote:
> I am having a performance problem with a query implemented within a
> server side function. If I use an SQL client(EMS Postgres) and manually
> generate the sql query I get about 100 times performance improvement
> over using the function.
>
> I've also tried using a prepared statement from my application  and
> observed a similar performance improvement over the the function.
>
> The table I am quering against has several hundred thousand records. I
> have indexes defined and I've run vacuum several times.
>
> Is there something basic I am missing here with the use of a function. I
> am no database expert, but my assumption was that a function would give
> me better results than in-line sql.
>
> I've seen a mailing list entry in another list that implied that the
> query planner for a function behaves differently than in-line sql.

For starters, can you show us the function, the manual sql query and the
schema, please?

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com

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