IBM QSAM (Queued Sequential Access Method) Interview Questions

 
1.
What is QSAM file?
2.
What is QSAM? Use of the QSAM? How it is used?
3.
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?