CICS Important Tips

TIP # 1 CICS

Use CALLs instead of LINKs in CICS
EXEC CICS LINK
- establishes a new run unit
- sets up environment
- Does CICS table-search
- For all this activities, it executes 1400 machine code instructions
CALL
- It executes around 12 machine code instructions
Just replacing EXEC CICS LINK with CALL statement on a case study, it was found that
Internal Transaction Response time improved 23 - 78 %
Total CPU Time improved 15 - 23 %
Dynamic storage use improved 11 - 30 %
* CALL used in the study is STATIC CALL . COBOL refered here is VS COBOL II

TIP # 2 CICS

You can use a COBOL CALL statement to call only a VS COBOL II or an Assembler language
program in the same load module as the calling program.
For calls to programs written in languages other than VS COBOL II, including other versions of
COBOL, you need to use the commands EXEC CICS LINK or EXEC CICS XCTL.

TIP # 3 CICS

Do you know how CICS was called initially ??
PUCICS!!!
PUCICS stands for Public Utilities Customer Information Control System.
After couple of years, it took the name CICS.

TIP #4 CICS

What is the difference between getting the system time with EIBTIME and ASKTIME
command?
ASKTIME = requests the current date and time
EIBTIME = field have the value at the task initiation time

TIP #5 CICS

To access the system values like date, time, Userid etc and store in a variable, one can use
EXEC CICS ASSIGN

TIP # 6 CICS

While doing a mass delete using a generic key, how can you determine the number of records
deleted?
By using the NUMREC(data-area) option with the generic key. Upon completion of the delete
the data-area will contain the number of records that are deleted.

TIP # 7 CICS

When generating Mapset, specify TIOAPX=YES for COBOL programs. YES generates a 12-
byte FILLER item at the beginning of each symbolic map. It should always be specified for
COBOL programs.

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