Q1
What is the purpose of COMMAREA in CICS?
COMMAREA (Communication Area) is used to pass data between programs or between transactions in pseudo-conversational programming.
Uses:
- Pass data between LINK/XCTL programs
- Save data between pseudo-conversational transactions
- Maximum size: 32KB
How it works:
- Calling program: COMMAREA option on LINK/XCTL/RETURN
- Called program: DFHCOMMAREA in LINKAGE SECTION
- Check EIBCALEN for length (0 = no COMMAREA)
* Calling program
EXEC CICS LINK
PROGRAM('SUBPROG')
COMMAREA(WS-DATA)
LENGTH(100)
END-EXEC.
* Called program
LINKAGE SECTION.
01 DFHCOMMAREA PIC X(100).
IF EIBCALEN > 0
MOVE DFHCOMMAREA TO WS-DATA
END-IF.
Q2
How to handle CICS RESP codes?
EXEC CICS command RESP(ws-resp). Check DFHRESP(NORMAL) for success. RESP2 has additional info. Always check after commands.
Q3
What is START command?
START schedules future transaction. EXEC CICS START TRANSID(trans) INTERVAL(time) FROM(data). Used for background processing.
Q4
How does BROWSE work in CICS?
STARTBR positions, READNEXT/READPREV retrieves, ENDBR ends. TOKEN for concurrent browses. Use for sequential VSAM access.
Q5
What is temporary storage?
TS queue stores data across tasks. WRITEQ TS writes, READQ TS reads, DELETEQ removes. MAIN (memory) or AUXILIARY (disk).
Q6
Explain HANDLE CONDITION.
Sets error labels: HANDLE CONDITION NOTFND(para). Jumps on condition. Obsolete - prefer RESP option for cleaner handling.
Q7
What causes ASRA abend?
Program check (S0Cx) in CICS. Common: S0C7 data exception, S0C4 protection. Check CEDF, examine dump for cause.
Q8
What is CEDA?
CEDA defines resources online. CEDA DEFINE PROGRAM/TRANSACTION/FILE. CEDA INSTALL activates. RDO (Resource Definition Online).
Q9
Explain transient data.
TD queues for sequential I/O. Intrapartition: CICS internal. Extrapartition: external datasets. Defined in DCT. Trigger level for automatic transaction start.
Q10
What is SYNCPOINT?
SYNCPOINT commits changes. SYNCPOINT ROLLBACK undoes since last sync. Use for transaction consistency. Implicit at task end.