| From: | Simon Riggs <simon(at)2ndquadrant(dot)com> |
|---|---|
| To: | Kris Jurka <books(at)ejurka(dot)com> |
| Cc: | Josh Berkus <josh(at)agliodbs(dot)com>, PostgreSQL - JDBC <pgsql-jdbc(at)postgresql(dot)org> |
| Subject: | Re: JDBC, prepared queries, and partitioning |
| Date: | 2008-02-13 20:34:24 |
| Message-ID: | 1202934864.16770.486.camel@ebony.site |
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| Thread: | |
| Lists: | pgsql-jdbc |
On Wed, 2008-02-13 at 13:51 -0500, Kris Jurka wrote:
>
> On Wed, 13 Feb 2008, Josh Berkus wrote:
>
> > Since JDBC always prepares and plan-caches queries, it makes it hard to use
> > partitioning with a database connected to a JDBC connection pool; successive
> > queries in the same session will select the wrong partition, or scan the
> > whole partition set.
> >
>
> It will never scan the wrong partition. It will always scan all
> partitions. The server is smart enough to not generate a plan that is not
> valid for only one parameter set.
>
> Using protocol version 2 will not prepare queries so constraint exclusion
> can be used. Just append protocolVersion=2 to your URL.
What about the prepare threshold?
--
Simon Riggs
2ndQuadrant http://www.2ndQuadrant.com
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