After completing this course, the student should be able to:
 

	Explain program development and preparation, including the use of ISQL
	Discuss error recovery practices and potential errors due to concurrent users
	Describe various considerations for program performance

Program Preparation and Support
Introduces the interactive tools available to support the preparation and testing of SQL statements and COBOL programs containing SQL.
 

	Overview of Program Development Overview of the steps in developing, preparing and testing a COBOL program that includes SQL statements.  Tools available to carry out those steps.
	ISQL Interactive testing of queries with ISQL.  The CHANGE and START commands to modify and rerun a query.  The EXIT command to leave ISQL.  ISQL limitations.  Choices for committing updates.
	Program Preparation    Purpose of the preprocess stage.  The SQLPREP EXEC or JCL EXEC to prepare a program. Data Integrity and Program Efficiency Covers issues such as preventing invalid updates and recovering from program failure.  The final lesson gives some hints on how to code programs to minimize the overhead in accessing tables.
	Error Recovery Committing updates at task completion.  Rollback of updates since the last commit point.  Definition of a unit of recovery.  SQL/DS's automatic committing of updates.  Purpose and use of the SQL COMMIT statement.  Purpose and use of the CICS commands CICS RETURN, CICS SYNCPOINT and SQL COMMIT WORK.  Implicit and explicit methods to cause the rollback of updates.  Automatic closing of the cursor at commit points.
	Concurrent Users Definition of locking.  Cursor Stability and Repeatable Read levels of isolation.  Where to specify the level of isolation.  Locksize at table creation time.
	Program Performance How program performance is affected by program design, table definition, SQL syntax, using an index by SQL/DS, and sorting.