25 Essential CICS Interview Questions

1. What is meant by Handle Condition? 

It transfers control to the para when the exceptional condition occurs for which as designed.

2. What is meant by Ignore Condition? 

No action to take. No more than 12 conditions are allowed in the same program. Once any IGNORE or HANDLE command is executed for a condition, the specification remains in effect until the program ends or another HANDLE or IGNORE command is executed.

 3. What is meant by PUSH and POP commands? 

Suspend and Reactivate all HANDLE CONDITION currently in effect.

 4. What are alternatives to HANDLE CONDITION? 

There are two alternatives: NO HANDLE and RESP condition. NO HANDLE will cause no action to be taken for any exceptional condition that occurs during the execution of a program. It should only be a special-purpose command. RESP option helps CICS place a response code after the command. The application program can check this code and proceed to the next level. When it has been coded, the HANDLE CONDITION does not have any effect.

 5. What is meant by a Basic locator for linkage (BLL)? 

The Base Locator for linkage (BLL) is an addressing convention used to address storage outside the Working Storage section of the program. If you use BLL for the input commands, it will improve the performance since the program would be accessing directly the input buffer outside the program. Also, if you use BLL for dynamic table loading, it will save the size of the application program since there is no requirement for any space reservation for the table in the program.

 6. What is meant by the SERVICE RELOAD statement?

It ensures addressability to a particular area defined in the linkage section.

 7. What is meant by the ADDRESS command? 

• It is to access information in the CICS system areas. You can use it in four ways:
•  CSA To access the common System area is the CICS system area defined by the system.
•  CWA To access the common work area, is a CICS system work area defined by the system programmer in SIT
•  (TCTUA) is a work area associated with a terminal. TCTUA defines as per terminal in TCT table.
•  TWA To access the Transaction work area (TWA) is a work area associated with a task. TWA is defined as one per task in PCT

 8. What is meant by the ASSIGN command? 

You can access the system values like date, time, userid, etc, and store them in a variable.

9. What is meant by EIB?

EIB stands for EXEC interface block. Some commonly used EIBs are as follows:

•  EIBAID
•  EIBCALEN
•  EIBDATE
•  EIBFN
•  EIBRCODE
•  EIBTASKN
•  Attention-id (1 byte0 length of DFHCOMMAREA (S94 COMP)
•  Date when this task started (S9(7) COMP-3, 000yyddd+)
•  Function code of the last command, which consists of 2 bytes, and the response code of the last command, which consists of 6 bytes.
•  Task number of this task (S9(7) COMP-3)

10. What do you know about the GETMAIN command? 

It is to obtain a certain amount of storage. It is possible by the storage control program SCP.

11. What do you know about the FREEMAIN command?

The FREEMAIN command you can use to release the storage.

 12. What is the difference between LINK and XCTL?

LINK: It is the command used to pass control from one program to another where the calling program expects the control to be passed back from the called program.

 XCTL: Over here the calling program does not expect the control to be passed back to it.

13. What is meant by the Reentrant program? 

It is a program that does not modify itself so that it can re-enter itself. This is very much required for a multithreading environment.

 14. What is the significance of EIBCALEN?

EIBCALEN is used to check if any data has been sent by the calling program, this is done by checking COMMAREA. If this is zero and there has been a program called another program then it can be assumed that there has been an error in calling.

 15. What is meant by LOAD command? 

It is used to load a program/table dynamically.

16. What is meant by PPT, PCT, and KCP?

PPT is called the processing program table. This is used to register all CICS application programs and BMS maps.

 PCT is called the program control table which is used to register the control information of all CICS transactions.

 KCP Is known as a task control program and is used for identifying and initializing transactions.

17. What is meant by the READ command with the GENERIC option?

is used to read a nonspecific record with a GENERIC key. This is helpful when you do not have the complete information about the key.

 18. What is meant by READ with the UPDATE command? 

It reads the record and maintains exclusive control over the record until the record is updated by a REWRITE command or the transaction is normally or abnormally completed. After reading the record, if found, that the update is not required then an unlock command is used to unlock the dataset to remove exclusive control.

 19. What is the difference between a conversational and pseudo-conversational program? 

After sending a map or message, a Conversational program will wait for a response.

 A pseudo-conversational program ends after sending a message without waiting for a response. The program includes a RETURN command.

 20. What is the effect of including the TRANSID in the RETURN command? 

The next time the end user presses an attention key, CICS will start the transaction specified in the TRANSID option (a new task it initiates).

 21. How does CICS use the PCT table? 

After a user enters a trans-id, CICS goes to the Program Control Table(PCT) and finds that trans-id. The table entry also contains the name of the program that executes when that trans-id is entered.

 22. How does CICS use the PPT table? 

After finding the program in the PCT, CICS goes to the Program Processing Table. It finds the program name in the table and the location on disk or in storage. If the program is already in storage, CICS starts the task. If not, CICS gets the program(load module), loads it into storage, and initiates the task. The PPT entry changed from on disk to in storage.

 23. What is the system Trans-id CEMT?

CEMT is the master terminal transaction that lets you display and change the CICS environment

 24. How do you load a new version of your program or map set?

CEMT Set PROGram(program name) NEwcopy

25.  How do you close a VSAM file in CICS?

CEMT Set DA(filename) CLOsed