Showing posts with label VSAM Interview Questions. Show all posts
Showing posts with label VSAM Interview Questions. Show all posts

What is the difference between CI( CONTROL INTERVAL)and CA(CONTROL AREA)


The CI is a single unit of transfer from secondary to main memory. Inside it will have freespace to store the records of fixed or variable size.
If u try to insert a new record to a ci which is not having any space to hold at that time the half of the record from this ci will be moved to some free ci. This splitting of ic in case of ci full is called CI splitt.
A collection of ci is called as CA. During the ci splitt if it is unable to find the free ci at that time the entire CA will be splitted into two and half will be moved to some free CA. This is called CA splitt. This is the primary mechanism of the VASM to store all the records inside your ksds in sorted order.

What is the procedure for running the batch job in mainframe?

Friends let me explain with an example:--

EG:-Adding two numbers

Step-1:- We need to compile that program and that compiled program(i.e Error free code) we need to keep in one Load Library (EG:-ABCD.GEEK.LOADLIB)

Step-2:- Now we need to execute this program giving PGM=ADD(Program Name) and the Load Libray name(ABCD.GEEK.LOADLIB)

Step-3:- Now In SYSOUT we can view the results

That's it this the process how to compile and execute a batch program

How do you convert flat files to VSAM files

Let's be a little more precise.We will take the tack that you will be creating a KSDS file.First, you need to know which field/s you will be using as the primary key and if you need, alternate keys. Sort the records by that field/s.Use IDCAMS REPRO to load the flat file into the VSAM file.

VSAM Tutorials ,VSAM KSDS EXAMPLES,IBM's MVS, OS/390

This Page contains VSAM Tutorials, VSAM Tips , VSAM Manuals

VSAM is a file system used in IBM's MVS, OS/390 and ZOS operating systems.
It offers standard sequential files, key Sequential and indexed files. In VSAM ,
Files can be read sequentially as well as randomly.