Initialization — EZTRIEVE programming language supplement

The application program prepares for QUICKSTART initialization as follows:

Set CKPT-PGM-NAME to the name of the EZTRIEVE program.

Set CKPT-FREQ below to an initial checkpoint frequency value. If the application is using a DBMS-specific checkpoint routine, then the frequency will be maintained within the Checkpoint Control table, and therefore the value in this field will act as a seed value only for the first run of the application. If the “NODBMS” version of the checkpoint routine is used, then this value will always determine the checkpoint frequency.

Set NBR-OF-SAMS to the number of sequential files to be managed by QUICKSTART.

For each SAM-DEFINITION, set the initial values of the following fields: Set SAMn-DDNAME to the 1-8 character DDNAME which should match the DDNAME in the execution JCL.

If file is to be opened for input, set SAMn-FILE-TYPE below to “I”. If file is to be opened for output, set it to “O”.

At the beginning of the program, invoke the QUICKSTART routine using the following syntax:

PERFORM CKPT-RTN
IF CKPT-RETURN-CODE= 'R'
     (perform any code necessary to effectively resume processing)
ELSE
    (perform normal start-up initialization)

To effectively resume execution following a restart, application program code might consist of any necessary DBMS repositionings, such as OPENing CURSORs.

Normal start-up initialization is any such code the application program needs to execute to prepare for Main-Line application program processing.

In some cases, restart code and normal Start-Up code are mutually exclusive. Fully analyze the requirements of the application program when coding this section.

If a restart is needed, QUICKSTART restores the Checkpoint Area to the state of the last checkpoint. Sequential files are OPENed, and if necessary, repositioned.