1. Suppose I have a KSDS File. I have a Records like 1,2,3,4,5,6,...100. I want to read using Dynamic mode like from 10 the Record onwards like, 10,12,14,16,18,....60. Wat is the command for this?

By using START command
Example :

START filename
KEY is EQUAL TO keyname
[INVALID KEY ...........]
END-START


PERFORM UNTIL end-of-file
READ filename NEXT RECORD
AT END
SET end-of-file TO TRUE
END-READ
END-PERFORM

2. What is QSAM? Use of the QSAM? How it is used?

QSAM (Queued Sequential access method), it's a sequential
file. Correct me if i am wrong.

3. What is QSAM file?

Queued sequential access method.similar to ESDS data set