JayBird Jboss firebird-ds.xml configuration doubt

Dear Members,


I am working in JBoss and Firebird. In jboss repository there is a file
1. firebird-ds.xml
http://cvs.sourceforge.net/viewcvs.py/*checkout*/jboss/jbosscx/src/etc/example-config/firebird-ds.xml?rev=1.2.2.2

It is different from other *-ds.xml (mostly). For
example in oracle-ds.xml

//snippet
<datasources>
<local-tx-datasource>
<jndi-name>OracleDS</jndi-name>

<connection-url>jdbcracle:thin:@youroraclehost:1521:yoursid</connection-url>

<driver-class>oracle.jdbc.driver.OracleDriver</driver-class>
<user-name>x</user-name>
<password>y</password>

</local-tx-datasource>
</datasources>
//end of snippet

On study about JBoss & J2ee I learned that in firebird-ds.xml you have configured to plug your own MangedConnectionFactory.
Is it so? Is it provides any performance gain than default manged connection factory?
Or do I provide configuration like other DBs as below ,

//snippet
// (local transaction - my application needs local transaction)
<datasources>

<local-tx-datasource>
<jndi-name>FireBirdDS</jndi-name>

<connection-url>jdbc:firebirdsql:localhost/3050:c:/Temp/Test.FDB</connection-url>

<driver-class>org.firebirdsql.jdbc.FBDriver</driver-class>
<user-name>sysdba</user-name>
<password>masterkey</password>
</local-tx-datasource>
</datasources>

//end of snippet


Even I commented out XA-transaction within tx-connection factory and modified rar.xml for local transaction.
But I am not sure of having tx-connection-factory entries of yours. Is there is any advantage in using
FBManagedConnectionFactory over default Jboss's factory
please do let me know about it.

S.Karthick