Hello,
We have been using postgreSQL for several years and we have just upgraded the jdbc driver (along with the db server) to version 9. As a result, we are getting poor performance with the new configuration: operations that took about 10 seconds using postgresql-8.4-701.jdbc4.jar take more than 2 minutes now.
To be more accurate, our application relies on some kind of init function that uses select queries involving metadata and ordinary data.
1. This operation takes about 12 seconds when our application is running with postgresql-8.4-701.jdbc4.jar. It also takes 12 or 15 seconds with postgresql-9.0dev-800.jdbc3.jar.
However, it takes more than 120(!) seconds using postgresql-9.0-801.jdbc3.jar or later versions.
2. Our guess is that metadata functions have become much slower since 9.0-801. We also found that many more requests are generated by the metadata functions. About 1200 request are sent to the database server when running postgresql-8.4-701.jdbc4.jar, more than 2000 when running postgresql-9.1-902.jdbc4.jar.
Methods such as get getIndexInfo() from AbstractJdbc2DatabaseMetaData seem to have changed a lot, but there are probably other major changes.
3. Can you confirm that changes in the metadata functions of the JDBC driver might explain the drop in performance ?
Is there any workaround that would save us from major surgery in our code ?
Can we use postgresql-9.0dev-800.jdbc3.jar instead of later versions ?
Is it safe to use postgresql-8.4-701.jdbc4.jar against a 9.0 server ?
Thanks for your help.
Best regards,
Mathieu Benhamou
CEGEDIM-SRH