DC Programming Techniques

This chapter discusses programming techniques used to request DC services. Functionally similar DC DML statements are presented together; sample code that demonstrates typical usage of each statement is included. The DC DML functions are divided into these categories:

Controlling the flow of processing in the different levels of your task
Retrieving task-related information-Accessing system, terminal, and user information related to the current task
Maintaining online data integrity-Monitoring concurrent database access locking database records across tasks
Managing tables-Adding and deleting tables from the program pool
Retrieving the current time and date-Accessing the time and date from the DC system
Writing to the journal file-Writing task-defined records to the journal file
Collecting DC statistics-Accessing run-time transaction statistics
Sending messages-Transmitting messages to other terminals, the user, and the log file
Writing to a printer-Directing data to printer devices
Writing JCL to a JES2 internal reader-Sending a JCL stream from the application program to a JES2 internal reader
Modifying a task's priority-Changing the dispatching priority of a task
Initiating nonterminal tasks-Using nonterminal tasks
Controlling abend processing-Specifying the flow of control in the event of an abend
Establishing and posting events-Establishing and posting event control blocks

This section contains the following topics:

Passing Program Control

Retrieving Task-Related Information

Maintaining Data Integrity in the Online Environment

Managing Tables

Retrieving the Current Time and Date

Writing to the Journal File

Collecting DC Statistics

Sending Messages

Writing to a Printer

Writing JCL to a JES2 Internal Reader

Modifying a Task's Priority

Initiating Nonterminal Tasks

Controlling Abend Processing

Establishing and Posting Events