Re: Prepare Statement

On Mon, 14 Jun 2004, Jie Liang wrote:

> I have a question about performance, in SQL commands: there is a
> prepare/execute command, document says it will improve the performance
> while repeatly execute a statement. In java.sql: there is a
> PreparedStatement object, which can store precompiled SQL statement,
> document says it can improve the performance also.
> If I use java jdbc to connect postgresql database, which one I should
> use? Can I use both?
>

When using JDBC it is best to use the standard Statement/PreparedStatement
interfaces. It is possible to directly use PREPARE/EXECUTE, but this can
be handled by the driver. Let me give you a run down of the different
driver versions and their capabilities:

Current released version: can enable using PREPARE/EXECUTE behind the
scenes on PreparedStatement by casting the prepared statement to
PGStatement and issuing setUseServerPrepare.

Current cvs version: can enable using PREPARE/EXECUTE by setting an
execution threshold that will turn it on when reached. This threshold can
be set at a number of levels, see the following for more information

http://www.ejurka.com/pgsql/docs/cvs/ch09s05.html

Soon to be committed cvs version: can directly use server prepared
statements without using the SQL level PREPARE/EXECUTE.

Kris Jurka