The Java EE Connector 1.6 specification allows a resource adapter to use the transaction-support attribute to specify the level of transaction support that the resource adapter handles. However, the resource adapter vendor does not have a mechanism to figure out the current transactional context in which a ManagedConnectionFactory is used.
If a ManagedConnectionFactory implements an optional interface called com.sun.appserv.connectors.spi.ConfigurableTransactionSupport, the GlassFish Server notifies the ManagedConnectionFactory of the transaction-support configured for the connector connection pool when the ManagedConnectionFactory instance is created for the pool. Connections obtained from the pool can then be used with a transaction level at or lower than the configured value. For example, a connection obtained from a pool that is set to XA_TRANSACTION could be used as a LOCAL resource in a last-agent-optimized transaction or in a non-transactional context.