Mainframe Interview Questions

There are some differences:

COBOL II supports structured programming by using in line Performs and explicit scope terminators. It introduces new features (EVALUATE, SET. TO TRUE, CALL BY CONTEXT, etc). It permits programs to be loaded and addressed above the 16-megabyte line .  It does not support many old features (READY TRACE, REPORT-WRITER, ISAM, etc.). It offers enhanced CICS support.

 -1 indicates the field is null

 0 indicates the field is not null

 -2 indicates the field is truncated

Autostatus is a protocol mode which causes the expansion of each DML statement to include a 'perform IDMS-Status' statement.

You must code EXEC CICS ASSIGN with the OPENID option.

They communicate via service MVS request calls.

While allocating KSDS Datasets, free space is declared at regular intervals at the time of initial loading. This is done because this free space is utilized for keeping the data arranged in sequence physically, even though inserted randomly.

Syntax:

SORT   file-1 ON ASCENDING/DESCENDING KEY key....

USING  file-2

GIVING file-3.

USING can be substituted by INPUT PROCEDURE IS para-1 THRU para-2

GIVING can be substituted by OUTPUT PROCEDURE IS para-1 THRU para-2.

file-1 is the sort workfile and must be described using SD entry in FILE SECTION.

file-2 is the input file for the SORT and must be described using an FD entry in FILE SECTION and SELECT clause in FILE CONTROL.

file-3 is the outfile from the SORT and must be described using an FD entry in FILE SECTION and SELECT clause in FILE CONTROL.

file-1, file-2 & file-3 should not be opened explicitly.

INPUT PROCEDURE is executed before the sort and records must be RELEASEd to the sort work file from the input procedure.

OUTPUT PROCEDURE is executed after all records have been sorted. Records from the sort work file must be RETURNed one at a time to the output procedure.

If any one want to restrict Trans-ID to single user, enter trans-id with ENQ. It won't allow any one else to use the same trans-id.