Performance/Issues with CMP and JBoss

Hi,

We currently have an JBoss web application that persists a byte array it
recieves (Using the EJB persistence API), and then tries to read it from the
Database again from further parsing. The application works really well with
the default Hypersonic datasource, but it will not work correctly when using
postgres as the datasource.

The current problem we seem to have is that the data is persisted ok (or at
least it seems to be in there with pgadmin), but cannot be read back out of
the database all the time (in fact for about 90% of the time), the current
behaviour of the application suggests it is trying to read it back out of
the database (using EntityManager.find()) before it has really been saved,
and thus fails to find the data. Do i have to tweak some settings in the
postgres.conf file ? i have tried turning off fsync (i do not want to do
this, for reliability reasons) and it performed far better. Can anyone
advise me on the changes i need to make to speed up the inserting of data, i
know that turning autocommit off is supposed to increase performance.

Thanks in advance,

Andy