connection pool in orbeon

Hi

how can i set max pool size for orbeon application. I set it in datasource-sql.xml file but it does not seems working.

<datasource>

   <driver-class-name>org.postgresql.Driver</driver-class-name>

    <uri>jdbc:postgresql://localhost:5432/survey_live</uri>
    <username>xyz</username>
    <password>xyz</password>

     <pool>
          <min-pool-size>10</min-pool-size>
          <max-pool-size>250</max-pool-size>
      </pool>

<idle-timeout-minutes>0</idle-timeout-minutes>
</datasource>