CONNX supports coordinated transactions for Oracle, Oracle Rdb, IBM DB2, CICS/VSAM, DBMS, and some OLE DB/ODBC Providers that support transactions through the ODBC and OLE-DB specification. This is accomplished through the ODBC SQLTransact API. Most applications have higher level wrappers around the ODBC and OLE API and methods for committing and rolling back transactions. Consult the documentation for your front-end application for details on the use of transactions.
Transactions are an SQL tool used to maintain database integrity. They are started before an SQL statement is executed. All SQL operations are recorded and are undone if a ROLLBACK transaction operation occurs. If a COMMIT transaction operation occurs, the database changes are made permanent, and the transaction log is cleared.
When a COMMIT command is issued, all of the statements in the transaction are applied to the database at once. When a ROLLBACK is issued, the statements are reversed, and the database is returned to its original state.
You can issue a rollback anytime before issuing a COMMIT command. If CONNX is exited in mid-operation, all commands are automatically rolled back. Issuing a COMMIT command saves any changes made up to that point.
Note: For CONNX for CICS/VSAM, COMMIT/ROLLBACK is implemented via the traditional EXEC SYNCPOINT and EXEC CICS SYNCPOINT ROLLBACK commands. The efficacy of these commands is contingent on whether the target VSAM files have been defined with journals or transaction logs.
