6 Using the Oracle Database Under openUTM

This chapter describes the Oracle Database-specific points that you should consider when using Oracle Database 10g release 2 (10.2) for BS2000/OSD under openUTM (Universal Transaction Monitor). The following topics are discussed in this chapter:

SQL Operations
UTM Operations

6.1 SQL Operations

UTM application program units must use embedded SQL. Explicit calls to any SQLLIB function calls or the Oracle Call Interface (OCI) are not allowed.

6.1.1 CONNECT

A connection is implicitly established when the UTM task is started. This connection uses the data specified in the open string. Further explicit CONNECT operations issued by the program units are not allowed.

6.1.2 COMMIT

An explicit COMMIT statement is not allowed in UTM program units. The openUTM will automatically issue one on a PEND RE, FI, SP, or FC operation.

6.1.3 ROLLBACK

An explicit ROLLBACK statement is not allowed in UTM program units. The openUTM will automatically issue a ROLLBACK statement on encountering a PEND ER, RS, FR, or RSET operation.

6.1.4 SAVEPOINT

The SAVEPOINT statement is not allowed in UTM program units.

6.1.5 Cursor Operations

A cursor is valid only until a PEND is run. Because of a possible task change during a PEND KP, PA, or PR, you cannot perform operations on a previously filled cursor such as OPEN or FETCH after a PEND KP, PA, or PR. However, you can open and fetch a new cursor after PEND KP. The alternative to using PEND KP is to use the PGWT-call (Refer to the openUTM manual, Programming Applications with KDCS for COBOL, C and C++), which will wait until input comes from the terminal, or to assign the same TACCLASS to subsequent programs after a PEND PA or PR.

6.1.6 Dynamic SQL

You may use dynamic SQL as described in the relevant Oracle Database Programmer's Guide to the Oracle Precompilers.

6.1.7 PL/SQL

COMMIT, ROLLBACK, CONNECT, and SAVEPOINT statements are not allowed in PL/SQL programs running under UTM.

6.1.8 Autocommit

Autocommit operations should be avoided because they violate the synchronization between Oracle Database and UTM transactions. Take care when using DDL operations, as these often contain implicit autocommits.

For example, DDL statements such as CREATE TABLE, DROP TABLE and CREATE INDEX are not allowed in a global transaction because they force pending work to be committed.

6.2 UTM Operations

This section describes the Oracle Database-specific points that you should consider when using UTM operations. The points in this section refer to PEND (Program Unit End) and RSET (Reset) operations. These operations represent the common synchronization point between openUTM and the Oracle Database.

When you issue a PEND call, UTM calls the Oracle Database internally for synchronization. When the PEND takes place:

The user dialog/transaction is detached from the executing task
Any resource that is still attached to the user is released

6.2.1 RSET and PEND RS

Resetting a UTM transaction implies rolling back the Oracle Database transaction.

6.2.2 PEND ER and PEND FR

When using these calls to terminate a UTM transaction, the Oracle Database transaction is also rolled back.

6.2.3 PEND KP, PEND PR, and PEND PA

These operations only end a UTM dialog step without affecting the corresponding Oracle Database transaction.

6.2.4 PEND RE, PEND FI, PEND SP, and PEND FC

These PEND calls cause an implicit COMMIT to be run. All cursors that have not been explicitly closed, are closed.