RM Switch Module Registration

In an XAR definition, you can specify that an RM switch module be registered either statically or dynamically:

Static registration: The switch module is registered for all transactions even if it does not participate in the transaction.
Dynamic registration: The switch module is registered for a transaction dynamically by the RM itself, with the first SQL call to the RM.

In general, dynamic registration is preferred because it requires less overhead, especially when multiple XARs have been defined.

Note: When using dynamic registration with Oracle or DB2, you might need to use the XAID directive when you compile your embedded SQL code. See SQL xa_open string Configuration Options for details.

As discussed in Building RM Switch Modules, both static and dynamic versions of an RM switch module are created during generation.

Once you have generated your switch modules, you specify either the dynamic or the static module as part of the XAR definition - the field module. This tells the enterprise server region what module to use and whether to register it statically or dynamically. See Defining XARs for more information.