Skip site navigation (1) Skip section navigation (2)

Re: does prepareThreshold work? forced to use old driver

From: Kris Jurka <books(at)ejurka(dot)com>
To: gene(at)sotech(dot)us
Cc: pgsql-jdbc(at)postgresql(dot)org, pgsql-performance(at)postgresql(dot)org
Subject: Re: does prepareThreshold work? forced to use old driver
Date: 2007-02-26 16:45:24
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-jdbcpgsql-performance

On Mon, 26 Feb 2007, Gene wrote:

> I've been having some serious performance issues with
> postgresql8.2/hibernate/jdbc due to postgres reusing bad cached query
> plans. It doesn't look at the parameter values and therefore does not
> use any partial indexes.
> After trying to set prepareThreshold=0 in the connection string which
> didnt work, even modifying the jdbc driver and forcing it to 0 and not
> working I realized that it must be being ignored. After giving up
> pretty much I tried a much older driver which doesn't use server
> prepared statements at all the problem has gone away and it is once
> again using the partial indexes. How can I get this to work properly
> on the new jdbc driver? I don't really like having to use a 2 year old
> driver to get good performance as you can imagine :)

Something must be going wrong in the setting to zero or your code may be 
setting it to non-zero at some later point.  I believe prepareThreshold=0 
should work.  Do you have a test case showing it doesn't?

Kris Jurka

In response to

pgsql-performance by date

Next:From: Mark StosbergDate: 2007-02-26 16:52:09
Subject: low memory usage reported by 'top' indicates poor tuning?
Previous:From: Madison KellyDate: 2007-02-26 16:29:14
Subject: Writting a "search engine" for a pgsql DB

pgsql-jdbc by date

Next:From: Kris JurkaDate: 2007-02-26 16:53:35
Subject: Re: Calling functions with table-based-type parametars
Previous:From: Heikki LinnakangasDate: 2007-02-26 16:19:29
Subject: Re: bug with PGXADataSource in JNDI

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group