IBM Mainframe Forum

Can anyone explain?

Is your question related to JCL or to using JCL procedures?

JCL Procedure Modifications are documented here if that's what you're looking for.

Both methods have their advantages. Some JCL values and parameters can be modified either as symbolics or overrides. A few can only be changed using one of the two methods.

An example is PGM= on an execute statement. You can make program name a symbolic but it cannot be overridden in a procedure..

Hi,

Overrides
1. Used to replace existing file with another file
Ex: You are using file infile1 as input in your job and want to use another file infile2 instead of infile1, you can override the infile1 with infile2 in the jcl to pick the infile2 instead of infile1.
Please check the syntax for file override.
2. you can use to dummy the infile.
Ex: if you don't want to process the input file, but still want to run the job successfully, you can override the input file with DUMMY.

Symbolic parameters
1. This is very powerful practice when you update the big jcl's. If in one jcl you are using many files and all the files share the same qualifier, using symbolic parameters you need to give only at once that particular qualifier. if you want to change the qualifier, you need to change only at one place.

There are some other differences and benfits also.
Both playes very important role in JCL.

Thanks,

Symbolic & Override parameters:
----------------------------------------

Please find the example below.hope it will be clear.

JCL for executing proc:
----------------------------

(OR)



PROC:
--------
Proc given below is catalog procedure.
LIBPFX= library prefix
DSNPFX = Dataset Prefix

Entries "Code'd" and corrected but not aligned completely.

Manakavisan,

First, read the forum rules - you will see that they say you should use the code tags when posting code - this keeps the code aligned properly making it easier to read.
Second, you have JCL errors in your posted code - you are missing commas, have spaces either side of an = character and your override is wrong: it should be

ok will follow it