Application-directed distributed unit of work
The application-directed distributed unit of work facility provides for the remote preparation and execution of SQL statements.
An application process at computer system A
can
connect to an application server at computer system B
by issuing a
CONNECT or a SET CONNECTION statement. The application process can then execute
any number of static and 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 the remote
unit of work facility, any number of application servers can participate in
the same unit of work. A commit or a rollback operation ends the unit of work.
An application-directed distributed unit of work uses a type 2 connection. A type 2 connection connects an application process to the identified application server, and establishes the rules for application-directed distributed units of work.
- Is always connectable
- Is either in the connected state or in the unconnected state
- Has zero or more connections.
Each connection of an application process is uniquely identified by the database alias of the application server for the connection.
- current and held
- current and release-pending
- dormant and held
- dormant and release-pending
A type 2 application process is initially in the unconnected state, and does not have any connections. A connection is initially in the current and held state.
