Commitment control concepts

This topic provides information to help you understand how commitment control works, how it interacts with your system, and how it interacts with other systems in your network.

• How commitment control works
  Commitment control is a function that allows you to define and process a group of changes to resources, such as database files or tables, as a transaction.
• How commit and rollback operations work
  Commit and rollback operations affect changes that are made under commitment control.
• Commitment definition
  You create a commitment definition when you use the Start Commitment Control (STRCMTCTL) command to start commitment control on your system. Also, DB2 Universal Database™ (UDB) for iSeries™ automatically creates a commitment definition when the isolation level is other than No Commit.
• How commitment control works with objects
  When you place an object under commitment control, it becomes a committable resource. It is registered with the commitment definition. It participates in each commit operation and rollback operation that occurs for that commitment definition.
• Commitment control and independent disk pools
  Independent disk pools and independent disk pool groups, can each have a separate i5/OS™ SQL database. You can use commitment control with these databases.
• Considerations and restrictions for commitment control
  The topic talks about miscellaneous considerations and restrictions for commitment control.
• Commitment control for batch applications
  Batch applications might or might not need commitment control. In some cases, a batch application can perform a single function of reading an input file and updating a master file. However, you can use commitment control for this type of application if it is important to start it again after an abnormal end.
• Two-phase commitment control
  Two-phase commitment control ensures that committable resources on multiple systems remain synchronized.
• XA transaction support for commitment control
  DB2 Universal Database™ (UDB) for iSeries™ can participate in X/Open global transactions.
• SQL server mode and thread-scoped transactions for commitment control
  Commitment definitions with job-scoped locks are normally scoped to an activation group.