Mainframe Interview Questions

Key Fields - (PROCOPT=K)

- Used to sequence the database and can't be changed

- It is the field within a segment, used to identify the occurrence of the segment

- Used to maintain the IMS segments in ascending sequence.

Search Fields - (PROCOPT=G)

- Used to search for a segment, without the segment being sequenced on that field

- A segment need not have a key or search field.

Both types of fields can be used to search the database.

A relative record dataset (RRDS) consists of a specified number of areas called slots. Each slot is identified by a relative record number (RRN) which indicates its relative position in the file.

An in-stream PROC is defined right in the jcl stream and doesn't reside in the proclib. This is an older technique associated with punched cards but it is still in use with setup and installation programs from vendors.

for the in-line perform instead of:

perform add-paragraph until switch = 'y'

you can code

perform until switch = 'y'

body of code

end-perform

body of code is the code from add-paragraph appearing in-line (ie right in the perform) instead of in a separate paragraph (out of line code)

- SQLCA stands for SQL Communication Area

- SQLCA is a structure of variables which are updated after every SQL statement’s execution

- Exactly only one SQLCA need to be provided to an application that contains executable SQL statements

- SQLCA is not applicable to JAVA application

- More than one SQLCA need to be provided for FORTRAN application

Use the LISTCAT command.

It is an MVS message that indicates the presence of a duplicate catalogue in the database. This problem can be fixed by removing one of the entries and then adding a new one.

Run VERIFY.

CEDA