Mainframe Interview Questions

IMS (Information Management System) is IBMs hierarchical database management system. It has mainly two components: IMS DB and IMS DC (Also know as IMS TM)

IMS DB - IMS/Database Manager as the name implies manages the IMS databases. It is used for physical storage creation and management and data retrieval.

IMS DC / IMS TM - IMS/Data Communications or IMS/Transaction Manager handles online transaction processing system.

All indicate dataset out of space. SD37 - no secondary allocation was specified. SB37 - end of vol. and no further volumes specified. SE37 - Max. of 16 extents already allocated.

SYSPRINT: All system output will appear under this DD card. Suppose you are copying a VSAM file using IDCAMS. Then, number of records processed, highest condition code etc.. will appear under sysprint. You cannot customise SYSPRINT output.

SYSIN: This is nothing but SYStem INstruction. Suppose, you want to sort a file on certain key. You have to have following command under SYSIN.

SORT FIELDS = (starting-col,length,data-type,A/D)

SUM FIELDS = NONE

DUMMY: Mainly used where user is intended to simulate a program without creating an output file.

TYPERUN=SCAN on the JOB card or use JSCAN.

TYPERUN=HOLD on the job card.

it is used for syntatical checks and direct job to spool and hold it.

Batch DL/I

MPP Mode - (Message Processing Program)

BMP Mode - (Batch Message Processing)

Out of space condition is raised.

A QUIESCE flushes all DB2 buffers on to the disk. This gives a correct snapshot of the database and should be used before and after any IMAGECOPY to maintain consistency.

IDD is the Integrated Data Dictionary. It contains information about the elements, record types, sets, maps and dialogues within the database.