Distributed unit of work

The application-directed distributed unit of work facility also provides for the remote preparation and execution of SQL statements in the same fashion as remote unit of work.

Like remote unit of work, an activation group at computer server A can connect to an application server at computer server B and execute any number of static or dynamic SQL statements that reference objects at B before ending the unit of work. All objects referenced in a single SQL statement must be managed by the same application server. However, unlike remote unit of work, any number of application servers can participate in the same unit of work. A commit or rollback operation ends the unit of work.

• Activation group states
  An activation group is always in the connected or unconnected state and has a set of zero or more connections. Each connection of an activation group is uniquely identified by the name of the application server of the connection.
• Connection states
  This topic discusses the different connection states and ways to change them.
• Activation group connection states
  A different application server can be established by the explicit or implicit execution of a CONNECT statement.
• When a connection is ended
  When a connection is ended, all resources that were acquired by the activation group through the connection and all resources that were used to create and maintain the connection are no longer allocated.
• Run with both RUW and DUW connection management
  Programs compiled with remote unit of work (RUW) connection management can be called by programs compiled with distributed unit of work (DUW) connection management. SET CONNECTION, RELEASE, and DISCONNECT statements can be used by the program compiled with RUW connection management to work with any of the active connections.