Mainframe Interview Questions

They are DEFINE CLUSTER, DATA and INDEX.

Primary key : a relational database constraint. Primary key consists of one or more columns that uniquely identify a row in the table. For a normalized relation, there is one designated primary key.

Unique index: a physical object that stores only unique values. There can be one or more unique indexes on a table.

It can be done by setting the record length’s size to more than half of the page’s size.

DeCLarations GENerator : used to create the host language copy books for the table    definitions. Also creates the DECLARE table.

DB2 precompiler (if embedded sql used), CICS translator (if CICS program), COBOL compiler, Link editor. If DB2 program, create plan by binding the DBRMs.

The following commands are available for the Program Control services:

LINK: To pass control to another program at the lower level, expecting to be returned. XCTL: To pass control to another program at the same level, not expecting to be returned.

RETURN:  To return to the next higher-level program or CICS. 

LOAD: To load a program. 

RELEASE: To release a program.

READNEXT reads the next record from a browse operation for any of the three VSAM files.

EXEC CICS READ

DATASET('FILENAME')

INTO(data-area)

RIDFLD(data-area)

KEYLENGTH(1)

GENERIC

LENGTH(WK-LEN)

END-EXEC.