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Q: What is the difference between COMP and COMP-3 in COBOL?
Answer:
COMP (COMPUTATIONAL) - Pure binary format
- Stored in binary (base-2)
- Used for subscripts and counts
- Efficient for arithmetic operations
- PIC S9(4) COMP = 2 bytes
- PIC S9(9) COMP = 4 bytes
COMP-3 (PACKED DECIMAL)
- Each digit takes 4 bits (nibble)
- Last nibble holds sign
- Used for business calculations
- PIC S9(5) COMP-3 = 3 bytes
- Formula: (n+1)/2 rounded up
When to use:
- COMP - Array subscripts, counters, loops
- COMP-3 - Money, quantities, business data
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Q: When should I use COMMIT in DB2?
Answer:
COMMIT saves all changes since the last COMMIT and releases locks.
When to COMMIT:
- After processing a logical unit of work
- Periodically in long-running batch (every N records)
- Before ending the program successfully
Frequency Guidelines:
- Too frequent: Performance overhead
- Too rare: Lock contention, large log
- Typical: Every 100-1000 records in batch
Best Practice:
MOVE 0 TO WS-COMMIT-COUNT.
PERFORM PROCESS-RECORD.
ADD 1 TO WS-COMMIT-COUNT.
IF WS-COMMIT-COUNT >= 500
EXEC SQL COMMIT END-EXEC
MOVE 0 TO WS-COMMIT-COUNT
END-IF.
Note: In CICS, syncpoint (COMMIT) happens automatically at task end. Explicit SYNCPOINT is rarely needed.
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Q: What is pseudo-conversational programming in CICS?
Answer:
Pseudo-conversational programming is a technique where the program ends between user interactions, freeing system resources.
How it works:
- Program sends screen to user and ends (RETURN TRANSID)
- User enters data and presses Enter
- CICS starts a new task with same program
- Program retrieves saved data from COMMAREA
- Process continues
Benefits:
- Efficient resource usage
- Better response times
- More concurrent users
Implementation:
* End task, wait for user
EXEC CICS RETURN
TRANSID('MENU')
COMMAREA(WS-COMM)
LENGTH(100)
END-EXEC.
* On return, check EIBCALEN
IF EIBCALEN = 0
PERFORM FIRST-TIME
ELSE
MOVE DFHCOMMAREA TO WS-COMM
PERFORM PROCESS-INPUT
END-IF.
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Q: What is a copybook and why is it used?
Answer:
A copybook is a reusable code file that can be included in multiple programs using the COPY statement.
Uses:
- Standard record layouts
- Common working storage definitions
- Reusable paragraphs
- Ensures consistency across programs
Syntax:
COPY EMPREC. COPY EMPREC REPLACING ==EMP== BY ==WS-EMP==.
Benefits:
- Reduces code duplication
- Easier maintenance
- Standard definitions across team
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Q: What is the purpose of COMMAREA in CICS?
Answer:
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.
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Q: What is the difference between COMP and COMP-3?
Answer:
COMP (Binary) stores data in binary format, taking 2, 4, or 8 bytes. COMP-3 (Packed Decimal) stores two digits per byte with the sign in the last nibble, more efficient for decimal arithmetic. COMP is faster for calculations while COMP-3 saves space for large decimal numbers.
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Q: How to handle variable length records?
Answer:
Use RECORD CONTAINS min TO max CHARACTERS clause in FD. Define RECORD-LENGTH field in the record. For VSAM, use RECORD VARYING IN SIZE. Access actual length via LENGTH OF or special register. Handle both fixed and variable portions appropriately.
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Q: How does INSPECT work?
Answer:
INSPECT examines/modifies string contents. INSPECT field TALLYING counter FOR ALL 'X'. INSPECT field REPLACING ALL 'A' BY 'B'. INSPECT field CONVERTING 'abc' TO '123'. Useful for data validation, transformation, and counting characters.
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Q: How to handle large objects (LOB)?
Answer:
BLOB/CLOB/DBCLOB for large data. Stored in auxiliary tablespace. Use LOB locators for efficiency. FETCH with INTO :lobvar. INSERT with CLOB(text). LOG NO for LOB tablespace optional.
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Q: What is dynamic SQL?
Answer:
Dynamic SQL constructed at runtime. PREPARE creates executable. EXECUTE runs it. EXECUTE IMMEDIATE for one-time. DECLARE CURSOR for queries. More flexible but less efficient than static. Security concerns (injection).
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Q: What is USAGE clause?
Answer:
USAGE specifies internal data representation. DISPLAY (default)=character, COMP/BINARY=binary, COMP-3/PACKED-DECIMAL=packed, COMP-1=single float, COMP-2=double float. Affects storage size and arithmetic performance.
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Q: Explain database design normalization
Answer:
1NF: atomic values, no repeating groups. 2NF: 1NF + no partial dependencies. 3NF: 2NF + no transitive dependencies. BCNF: stricter 3NF. Higher forms reduce redundancy. Denormalize for performance. Balance is key.
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Q: How to handle packed decimal data?
Answer:
Packed decimal (COMP-3) stores 2 digits per byte, sign in low nibble. PIC S9(5) COMP-3 uses 3 bytes. For I/O, often must convert to display. Use MOVE to display field or NUMVAL function. Handle sign separately if needed.
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Q: What is encoding scheme?
Answer:
Encoding defines character representation. EBCDIC for mainframe. ASCII for open systems. Unicode for international. CCSID specifies exact encoding. Mixed encoding needs careful handling. TRANSLATE for conversion.
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Q: How to handle CLOB in COBOL?
Answer:
Declare: 01 CLOB-VAR SQL TYPE IS CLOB(1M). Or use LOB locator: 01 CLOB-LOC SQL TYPE IS CLOB_LOCATOR. FREE LOCATOR releases. DBMS_LOB procedures for manipulation. Large CLOBs need special handling.
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Q: What is GLOBAL clause?
Answer:
GLOBAL makes data available to nested programs. 01 WS-COUNTER PIC 9(5) GLOBAL. Nested programs can reference without passing as parameters. Use sparingly; explicit passing preferred. File definitions can also be GLOBAL.
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Q: What is SAME RECORD AREA?
Answer:
SAME RECORD AREA clause specifies files share buffer: SAME RECORD AREA FOR FILE-1 FILE-2. Records of different files occupy same memory. Reading one file overlays other's record. Saves memory but requires careful coding.
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Q: What is Distributed Data Facility (DDF)?
Answer:
DDF enables remote DB2 access. TCP/IP and SNA connectivity. DRDA protocol. Location name identifies target. Three-part names: location.schema.table. Network security considerations.
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Q: What is RECORDING MODE for files?
Answer:
RECORDING MODE specifies record format: F=fixed, V=variable, U=undefined, S=spanned. RECORDING MODE IS V for variable records. Affects how records are blocked and how length is tracked. Must match JCL DCB specifications.
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Q: How to handle EBCDIC/ASCII conversion?
Answer:
COBOL on mainframe uses EBCDIC natively. For ASCII conversion: use INSPECT CONVERTING, or file translation (JCL), or LE functions. NATIONAL-OF and DISPLAY-OF for Unicode. Different collating sequences affect SORT and comparisons.
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Q: What is ORGANIZATION clause?
Answer:
ORGANIZATION specifies file structure: SEQUENTIAL (default), INDEXED (VSAM KSDS), RELATIVE (RRDS). Determines access methods available. INDEXED requires RECORD KEY. ACCESS MODE can be SEQUENTIAL, RANDOM, or DYNAMIC.
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Q: What is CI and CA in VSAM?
Answer:
CI (Control Interval) is I/O unit, like block. Contains records, free space, control info. CA (Control Area) is group of CIs. CISIZE affects performance. CI split when full. CA split more expensive.
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Q: What is PIC clause editing?
Answer:
Picture editing characters: Z=zero suppress, *=check protect, +=sign, -=negative, CR/DB=credit/debit, $=currency, .=decimal, ,=comma, B=blank. Example: PIC ,ZZ9.99- displays $ 123.45-. Insertion characters add to display.
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Q: Explain FREESPACE parameter
Answer:
FREESPACE(cipct capct). CI percent free for inserts. CA percent free for splits. FREESPACE(20 10) leaves 20% CI, 10% CA free. More freespace reduces splits but uses more space. Tune based on activity.
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Q: What is SPANNED record?
Answer:
Spanned records exceed CI size, span multiple CIs. DEFINE CLUSTER ... RECORDSIZE(avg max) SPANNED. CI too small for max record. Performance impact. Use appropriately sized CI when possible.
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Q: How to handle OCCURS INDEXED tables?
Answer:
Indexed tables use INDEXED BY: 05 TBL OCCURS 10 INDEXED BY IDX. SET IDX TO 1 initializes. SET IDX UP BY 1 increments. SEARCH uses index implicitly. More efficient than subscript-index conversion.
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Q: Explain WRITE BEFORE/AFTER ADVANCING
Answer:
ADVANCING controls line spacing for print files. WRITE rec AFTER ADVANCING 2 LINES skips 2 lines first. WRITE rec BEFORE ADVANCING PAGE starts new page after. WRITE rec AFTER PAGE goes to new page first. Controls report formatting.
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Q: What is READY TRACE?
Answer:
READY TRACE turns on paragraph tracing. Shows paragraph names as executed. RESET TRACE turns off. Must compile with debugging option. Output goes to SYSOUT. Replaced by better debuggers but useful for quick flow analysis.
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Q: Explain SYMBOLIC CHARACTERS
Answer:
SPECIAL-NAMES. SYMBOLIC CHARACTERS NULL-CHAR IS 1. Assigns name to ordinal position in collating sequence. Position 1 is X'00' in EBCDIC. Use: MOVE NULL-CHAR TO field. Define non-printable characters readably.
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Q: What is CISIZE calculation?
Answer:
CISIZE must hold at least one record plus overhead. Formula complex. Let system default usually best. Common sizes: 4096, 8192, 16384. Larger CI can improve sequential, hurt random.
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Q: Explain COPY REPLACING
Answer:
COPY copybook REPLACING ==:TAG:== BY ==WS-==. Substitutes text during copy. Pseudo-text delimiters ==. Can replace identifiers, literals, words. Multiple REPLACING clauses allowed. Useful for generic copybooks.
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Q: What is EXEC CICS structure?
Answer:
EXEC CICS marks CICS commands. EXEC CICS READ FILE('name') INTO(area) RIDFLD(key) END-EXEC. Commands: READ, WRITE, SEND, RECEIVE, LINK, XCTL. RESP and RESP2 capture return codes. Translator converts to CALL.
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Q: How to handle variable length KSDS?
Answer:
Define with RECORDSIZE(avg max). Read/write variable length records. COBOL RECORD VARYING clause. Key position fixed. Read returns actual length. Write length implicit from record.
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Q: How to improve KSDS performance?
Answer:
Appropriate CISIZE, FREESPACE. Adequate buffers (BUFND/BUFNI). Index in cache if possible. IMBED obsolete. Keep file organized (REORG). Monitor CA/CI splits. Sequential access for bulk.
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Q: Explain MASSINSERT?
Answer:
MASSINSERT optimizes bulk sequential inserts. System defers CI splits. Better performance for loads. Implicit with REPRO. COBOL can hint with APPLY WRITE-ONLY style.
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Q: Explain LOG parameter
Answer:
LOG(NONE/UNDO/ALL) specifies recovery logging. UNDO for backward recovery. ALL for forward and backward. NONE for no logging. Used with transactional systems. Most batch uses NONE.
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Q: What is REGION parameter?
Answer:
REGION specifies memory limit. REGION=0M means no limit (use system default). REGION=4M limits to 4MB. On JOB card affects all steps, on EXEC affects that step. Below 16M line: REGION=2048K. Modern systems often use REGION=0M.
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Q: What is STORAGECLASS?
Answer:
SMS STORAGECLASS for VSAM placement. STORCLAS on DEFINE. Controls performance, availability. ACS routines may assign. Modern storage management. Replaces explicit volume specifications.
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Q: How does OUTPUT statement work?
Answer:
OUTPUT defines SYSOUT processing options. //OUT1 OUTPUT CLASS=A,DEST=LOCAL,COPIES=2. Reference: //SYSOUT DD SYSOUT=*,OUTPUT=*.OUT1. Centralizes output attributes. Can specify JESDS for JES-level control. Forms, burst options available.
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Q: What is SPANNED records impact?
Answer:
Spanned records span CIs. More I/O for spanned record access. CI header overhead per CI. Avoid if possible by larger CI. Performance degradation for random access.
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Q: What is JCLLIB ORDER?
Answer:
JCLLIB ORDER specifies procedure library search order. //JOBNAME JOB ... // JCLLIB ORDER=(PROC.LIB1,PROC.LIB2). Searched for INCLUDE and EXEC procname. Takes precedence over JES2/3 proclibs. Must be before first EXEC statement.
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Q: What is FREESPACE distribution?
Answer:
FREESPACE spread across CIs and CAs. Initial load distributes evenly. After activity, distribution varies. REORG restores even distribution. Monitor CI/CA splits for tuning.
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Q: What is COMMAREA and how to use it?
Answer:
COMMAREA (Communication Area) passes data between programs and transactions. EXEC CICS LINK/XCTL COMMAREA(data) LENGTH(len). Receiving program has DFHCOMMAREA in LINKAGE. Max 32KB. Preserved across pseudo-conversational iterations.
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Q: What is pseudo-conversational programming?
Answer:
Pseudo-conversational ends task after sending screen, restarts on input. EXEC CICS RETURN TRANSID(trans) COMMAREA(data). Saves resources - no task waiting for user. Must restore state from COMMAREA. Standard CICS approach.
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Q: How to handle CICS RESP codes?
Answer:
RESP and RESP2 capture command results. EXEC CICS command RESP(ws-resp) RESP2(ws-resp2). Check DFHRESP(NORMAL) for success. RESP contains condition. RESP2 has additional info. Always check after commands.
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Q: What is EXEC CICS READ?
Answer:
READ retrieves VSAM record. EXEC CICS READ FILE(name) INTO(area) RIDFLD(key) LENGTH(len). Optionally: UPDATE for update intent, KEYLENGTH for partial key. Generic key with GENERIC/KEYLENGTH. Returns NOTFND if missing.
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Q: Explain LINK vs XCTL
Answer:
LINK calls program and returns. EXEC CICS LINK PROGRAM(name). Calling program resumes after LINK. XCTL transfers permanently - no return. EXEC CICS XCTL PROGRAM(name). Use LINK for subroutines, XCTL for navigation.
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Q: Explain PARM parameter
Answer:
PARM passes data to program. EXEC PGM=PROG,PARM='value'. Max 100 characters. Program receives length prefix. PARM='abc,xyz' passes as one string. Program parses. Special chars need quotes. Alternative: SYSIN for larger data.
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Q: Explain CICS task and transaction
Answer:
Transaction is unit of work started by TRANSID. Task is CICS execution instance. One transaction may create multiple tasks. Task has TCA (Task Control Area). EIBTRNID has transaction ID. Concurrent tasks share resources.
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Q: How to use temporary storage?
Answer:
TS queue stores data across tasks. EXEC CICS WRITEQ TS QUEUE(name) FROM(data). READQ retrieves. DELETEQ removes. ITEM number for multiple items. MAIN/AUXILIARY for storage type. Named by string.
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Q: How to do file BROWSE?
Answer:
BROWSE reads sequentially. EXEC CICS STARTBR FILE(name) RIDFLD(key). READNEXT/READPREV in loop. ENDBR ends browse. TOKEN for concurrent browses. Can use generic key to position.
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Q: What is WRITE command?
Answer:
WRITE adds new record. EXEC CICS WRITE FILE(name) FROM(data) RIDFLD(key) LENGTH(len). DUPREC condition if key exists. KEYLENGTH for generic. MASSINSERT optimizes bulk loads.
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Q: How to SYNCPOINT?
Answer:
SYNCPOINT commits changes. EXEC CICS SYNCPOINT. Makes updates permanent. Or SYNCPOINT ROLLBACK undoes since last sync. Implicit syncpoint at task end. Use for transaction consistency.
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Q: What is ABEND command?
Answer:
ABEND deliberately terminates. EXEC CICS ABEND ABCODE('XXXX'). Causes transaction abend with code. NODUMP suppresses dump. CANCEL removes HANDLE ABEND first. Use for unrecoverable errors.
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Q: How to use INQUIRE command?
Answer:
INQUIRE retrieves resource status. EXEC CICS INQUIRE FILE(name) OPENSTATUS(ws-status). INQUIRE TRANSACTION, PROGRAM, etc. Returns current state. Use for dynamic decisions.
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Q: Explain AVGREC parameter
Answer:
AVGREC specifies space in record units. AVGREC=U (units), K (thousands), M (millions). SPACE=(80,(100,10),,,ROUND) with AVGREC=K means 100,000 records. Easier than calculating tracks. System converts to tracks.
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Q: Explain CICS regions
Answer:
CICS region is address space. TOR (Terminal Owning) owns terminals. AOR (Application Owning) runs programs. FOR (File Owning) owns files. MRO connects regions. Workload distribution.
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Q: What is JESDS parameter?
Answer:
JESDS specifies JES dataset for OUTPUT. JESDS=ALL creates JESMSGLG, JESJCL, JESYSMSG. JESDS=LOG for JESMSGLG only. On OUTPUT statement. Controls system output generation. Used for output management.
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Q: What is CHANNEL/CONTAINER?
Answer:
Channels group containers for data passing. EXEC CICS PUT CONTAINER(name) CHANNEL(chan) FROM(data). GET retrieves. Modern alternative to COMMAREA. No 32KB limit. Typed data support.
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Q: Explain ASKTIME/FORMATTIME
Answer:
ASKTIME gets current time. EXEC CICS ASKTIME ABSTIME(ws-abstime). FORMATTIME converts to readable. FORMATTIME ABSTIME(ws-abstime) DATESEP('/') TIMESEP(':'). Formatting options available.
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Q: How to force uncataloged?
Answer:
VOL=SER=volume forces uncataloged access. DISP=(OLD,KEEP). System searches specified volume, not catalog. UNIT required. Bypasses catalog entirely. Useful for specific volume access. Security still applies.
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Q: How to use ENQ/DEQ?
Answer:
ENQ serializes resources. EXEC CICS ENQ RESOURCE(name) LENGTH(len). DEQ releases. Prevents concurrent access. NOSUSPEND returns immediately if busy. Use for data integrity.
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Q: How to WRITEQ with REWRITE?
Answer:
WRITEQ TS with REWRITE updates existing item. EXEC CICS WRITEQ TS QUEUE(name) FROM(data) REWRITE ITEM(n). Without REWRITE, adds new item. ITEM must exist for REWRITE.
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Q: What is LENGTH in commands?
Answer:
LENGTH specifies data size. LENGTH(ws-len). Required for variable data. Set before RECEIVE. Check after READ for actual length. FLENGTH for fullword. Some commands have defaults.
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Q: What is NOHANDLE option?
Answer:
NOHANDLE suppresses condition handling. EXEC CICS command NOHANDLE RESP(ws-resp). Program handles all conditions. No HANDLE CONDITION invoked. Cleaner error handling. Recommended approach.
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Q: How to do interval control?
Answer:
START with INTERVAL/AFTER for delayed execution. EXEC CICS START TRANSID(xx) INTERVAL(001000). Or AFTER HOURS(1) MINUTES(30). For scheduled background work. Data via FROM or CHANNEL.
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Q: What is IMMEDIATE option?
Answer:
IMMEDIATE on RETURN returns without COMMAREA. EXEC CICS RETURN IMMEDIATE. Next input starts fresh - no continuation. Use when pseudo-conv not needed.
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Q: What is FREE parameter?
Answer:
FREE specifies when to release allocation. FREE=END (default) at step end. FREE=CLOSE when file closed. FREE=CLOSE allows reuse within step. Reduces concurrent allocations. Helps resource-constrained systems.
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Q: What is KEYLENGTH option?
Answer:
KEYLENGTH specifies key portion for generic access. EXEC CICS READ FILE RIDFLD(partial) KEYLENGTH(4) GENERIC. Finds first matching prefix. Use with GTEQ for range.
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Q: What is SYSID?
Answer:
SYSID identifies CICS system. 4-character name. EXEC CICS ASSIGN SYSID(ws-sysid). Or in RDO definitions. Used for MRO routing, function shipping. Remote file/program SYSID option.
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Q: Explain SUSPEND command
Answer:
SUSPEND yields control to other tasks. EXEC CICS SUSPEND. Allows multitasking. Task resumes when dispatched. Use sparingly. May help long-running tasks. Usually unnecessary.
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Q: How to use WAIT EVENT?
Answer:
WAIT suspends until event. EXEC CICS WAIT EVENT ECBLIST(ecb-list). Multiple ECBs. Returns when any posted. Used for synchronization. Timer events, external events.
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Q: Explain DD PATH statement?
Answer:
PATH specifies Unix/USS file. PATH='/u/user/file'. Used instead of DSN. PATHDISP for disposition. PATHOPTS for options. PATHMODE for permissions. Integrates USS files into batch JCL.
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Q: What is FILEDATA parameter?
Answer:
FILEDATA specifies DCB for NFS/USS. FILEDATA=TEXT or BINARY. TEXT handles line endings. BINARY transfers unchanged. On PATH DD statements. Affects how data converted between systems.
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Q: How to use RETRIEVE command?
Answer:
RETRIEVE gets data passed via START. EXEC CICS RETRIEVE INTO(area) LENGTH(len). Data from START FROM parameter. Or RETRIEVE CHANNEL for containers. One retrieve per start.
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Q: What causes INVALID DATA SET NAME?
Answer:
Dataset name violates rules: 44 char max, qualifier 8 max, start with letter/national, periods separate qualifiers, no double periods, no special characters. Check spelling, length, valid characters.
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Q: How to allocate SYSDA?
Answer:
UNIT=SYSDA for disk. Generic device group. Installation defines SYSDA contents. Usually includes all available disk. SMS may direct allocation. UNIT=3390 for specific device type. SYSDA preferred for portability.
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Q: What is LRECL=X?
Answer:
LRECL=X means system-determined length. Usually for RECFM=U or special files. System calculates based on BLKSIZE or file characteristics. Not common for normal datasets. Used with certain utilities.
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Q: What is DATACLAS parameter?
Answer:
DATACLAS assigns SMS data class. DATACLAS=classname. Defines DCB attributes, space, data type. ACS routines may assign automatically. Overrides explicit DCB. Simplifies JCL. Installation-defined classes.
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Q: How to use CURSOR option?
Answer:
CURSOR positions cursor on SEND MAP. EXEC CICS SEND MAP CURSOR(pos). Position number from 0. Or CURSOR option in symbolic map (-1 in length field). Controls data entry flow.
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Q: Explain DATAONLY option
Answer:
DATAONLY sends only changed data. EXEC CICS SEND MAP DATAONLY FROM(data). No map formatting. Faster for updates. Fields must exist on screen. Use after initial MAPONLY.
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Q: What is FRSET?
Answer:
FRSET (Field Reset) resets MDTs. EXEC CICS SEND MAP FRSET. Only changed fields transmitted back. Efficiency. Without FRSET, all unprotected transmitted. Use for repeat maps.
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Q: How to use ACCUM option?
Answer:
ACCUM accumulates map output. EXEC CICS SEND MAP ACCUM. Build complete screen before send. Final EXEC CICS SEND PAGE. For multi-map screens. Message building.
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Q: What is OVERFLOW condition?
Answer:
OVERFLOW when output exceeds page. During SEND with paging. Handle to manage paging. RESP check. Terminal specific limits. May need to restructure output.
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Q: Explain EROPT parameter?
Answer:
EROPT specifies error handling. DCB=(EROPT=ABE/ACC/SKP). ABE=abend on error, ACC=accept and continue, SKP=skip block. For tape I/O errors. Program may handle differently. Default is ABE.
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Q: How to use TRANSFORM?
Answer:
TRANSFORM converts data format. EXEC CICS TRANSFORM DATATOXML. XML/JSON transformations. Modern data exchange. Requires definitions. Simplifies integration.
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Q: What is INVOKE SERVICE?
Answer:
INVOKE SERVICE calls web service. EXEC CICS INVOKE SERVICE. PIPELINE processing. SOAP/REST support. Modern integration. Requires CICS TS 3.1+.
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Q: What is CICS Liberty?
Answer:
CICS Liberty embeds Java server. Run Java apps in CICS. RESTful services. Modern application development. Coexists with COBOL. Container environment.
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Q: Explain CICS DB2 connection
Answer:
CICS connects to DB2 via thread. EXEC SQL in CICS program. RCT (Resource Control Table) defines. Thread pool for efficiency. DB2 subsystem parameter.
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Q: What is CICS monitoring?
Answer:
CICS monitoring facilities. SMF 110 records. CICS statistics. Transaction analysis. Performance data. OMEGAMON for real-time. Capacity planning.
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Q: Explain CICS troubleshooting
Answer:
CEDF for debugging. CEMT for status. Dumps for abends. Trace for flow. CICS messages. Aux trace for detailed analysis. Systematic approach.
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Q: Explain COMMIT and ROLLBACK
Answer:
COMMIT makes changes permanent, releases locks. ROLLBACK undoes changes since last COMMIT. Implicit COMMIT at program end (normal). Implicit ROLLBACK on abend. Frequent COMMIT reduces lock duration and log usage.
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Q: How to handle RLS (Record Level Sharing)?
Answer:
RLS allows VSAM access without exclusive control. Define with SHAREOPTIONS and LOG. Enable RLS at VSAM level. CF lock structure coordinates. Better than old batch/CICS conflicts.
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Q: How to handle SMS conversion?
Answer:
SMS manages storage automatically. Migrate VSAM to SMS: DATACLAS, STORCLAS, MGMTCLAS. ACS routines for assignment. Remove explicit VOL/UNIT. Benefits: automation, management.
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Q: What is EXEC CICS SEND CONTROL?
Answer:
SEND CONTROL sends control functions. EXEC CICS SEND CONTROL ERASE FREEKB. Clears screen, unlocks keyboard. No map or data. Prepare terminal for next operation.
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Q: What is ISSUE ABEND?
Answer:
ISSUE ABEND requests dump without termination. EXEC CICS ISSUE ABEND. Diagnostic snapshot. Continue execution. Alternative to full ABEND. Debug technique.
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Q: How to handle CICS timeout?
Answer:
Set RTIMOUT on transaction. EXEC CICS HANDLE CONDITION ERROR. DTIMOUT for deadlock. Program design for cleanup. TIMEOUT condition raised.
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Q: How to use CICS WAIT JOURNALNAME?
Answer:
WAIT JOURNALNAME ensures journal write. EXEC CICS WAIT JOURNALNAME(jname). Synchronize journal I/O. For assured delivery. Recovery purposes.
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Q: How to write recursive CTE?
Answer:
WITH RECURSIVE cte AS (base-case UNION ALL recursive-case referencing cte) SELECT * FROM cte. For hierarchies: start with root, join to find children. DEPTH limit prevents infinite recursion.
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Q: Explain DB2 logging
Answer:
DB2 logs all changes for recovery. Active log (circular), archive log (offloaded). LOG YES/NO on DDL. COMMIT writes to log. Recovery uses logs. Log full causes issues - monitor usage.
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Q: What is data sharing?
Answer:
Data sharing allows multiple DB2s to access same data. Group of subsystems share data. Uses Coupling Facility for coordination. Provides availability, scalability. Complex but powerful for high availability.
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Q: What is the purpose of COPY statement?
Answer:
COPY includes copybook members at compile time, promoting code reuse and standardization. Syntax: COPY copybook-name. REPLACING clause allows field substitution. Copybooks typically contain record layouts, working-storage definitions, and common routines.
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Q: What is INITIALIZE and its options?
Answer:
INITIALIZE sets fields to default values: alphabetic to spaces, numeric to zeros. Options: REPLACING NUMERIC BY value, REPLACING ALPHANUMERIC BY value. Does not initialize FILLER or REDEFINES items. Useful for clearing record areas before processing.
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Q: How does ACCEPT and DISPLAY work?
Answer:
ACCEPT reads from console/system: ACCEPT WS-DATE FROM DATE, ACCEPT WS-INPUT FROM CONSOLE. DISPLAY writes to console: DISPLAY 'Message' WS-FIELD. UPON clause specifies destination. Limited in batch; mainly for debugging or simple interaction.
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Q: How to define and use indexes?
Answer:
INDEX defined with OCCURS: 05 WS-TABLE OCCURS 10 INDEXED BY WS-IDX. SET WS-IDX TO 5 sets position. SET WS-IDX UP/DOWN BY 1 changes position. Use SEARCH verb with index. More efficient than subscripts for table access.
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Q: What is DECLARATIVES section?
Answer:
DECLARATIVES contains USE procedures for exception handling. USE AFTER ERROR PROCEDURE ON file-name handles file errors. USE AFTER EXCEPTION handles specific conditions. Must be first in PROCEDURE DIVISION. END DECLARATIVES marks end.
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Q: What is profile table?
Answer:
Profile tables store user-specific optimizer settings. DSN_PROFILE_TABLE, DSN_PROFILE_ATTRIBUTES. Override defaults for specific statements. Use QUERYNO correlation. Advanced tuning technique.
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Q: Explain thread management
Answer:
Thread is DB2 connection. Allied thread for TSO/batch. DBAT (database access thread) for DDF. Pool thread for efficient reuse. Max threads controlled by zparm. Monitor active threads.
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Q: What is SYNCHRONIZED clause?
Answer:
SYNCHRONIZED aligns binary items on natural boundaries for efficient access. 01 WS-GROUP. 05 WS-CHAR PIC X. 05 WS-BINARY PIC S9(8) COMP SYNC. Adds slack bytes as needed. Can waste space but improves performance. RIGHT/LEFT options available.
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Q: What is NATIVE-BCD?
Answer:
NATIVE-BCD is native binary-coded decimal, digits stored one per byte. Less efficient than COMP-3 but simpler to inspect in dumps. Some shops prefer for debugging. Available through compiler options or USAGE clause variations.
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Q: What is REPLACE statement?
Answer:
REPLACE substitutes text during compilation. REPLACE ==OLD-TEXT== BY ==NEW-TEXT==. Active until REPLACE OFF or next REPLACE. Useful with copybooks for site-specific modifications. Different from COPY REPLACING-more global.
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Q: Explain SPECIAL-NAMES paragraph
Answer:
SPECIAL-NAMES maps system names to COBOL names. DECIMAL-POINT IS COMMA for European notation. CURRENCY SIGN IS '$'. SYMBOLIC CHARACTERS name = value. ALPHABET for custom collating. CLASS for character groups.
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Q: What is DEFINE PATH?
Answer:
PATH associates AIX for access. DEFINE PATH(NAME(path.name) PATHENTRY(aix.name)). Required to access via AIX. Open PATH in program, not AIX directly. UPDATE option allows updates via path.
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Q: What is LABEL RECORDS clause?
Answer:
LABEL RECORDS specifies header/trailer labels. STANDARD (default) for labeled tapes. OMITTED for unlabeled or disk. Now less relevant-mostly tapes. Compiler may accept but ignore for disk files. Required in some older programs.
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Q: Explain SPEED vs RECOVERY
Answer:
SPEED skips CI/CA recovery info during load. Faster but risky. RECOVERY (default) writes recovery info. If job abends, RECOVERY allows restart. SPEED needs complete reload if problem.
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Q: What is CLASS condition?
Answer:
CLASS tests character content. IF field IS NUMERIC/ALPHABETIC/ALPHABETIC-LOWER/ALPHABETIC-UPPER. Custom classes in SPECIAL-NAMES: CLASS VOWELS IS 'A' 'E' 'I' 'O' 'U'. Then IF char IS VOWELS. Useful for validation.
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Q: What is CURSOR IS clause?
Answer:
In Screen Section, CURSOR IS field-name positions cursor. ACCEPT screen-name WITH CURSOR. Runtime positions to specified field. Can set dynamically. Used in interactive COBOL (CICS typically handles cursor differently).
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Q: How to handle negative numbers?
Answer:
Sign stored in PIC S9. SIGN IS LEADING/TRAILING SEPARATE CHARACTER for explicit sign byte. COMP-3 sign in low nibble. Display: S9(5)- shows trailing minus. +9(5) shows sign always. DB/CR for accounting format.
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Q: What is LINEAR dataset?
Answer:
LINEAR VSAM is byte-addressable. No record structure. Used by DB2 tablespaces, system software. DEFINE CLUSTER LINEAR. Accessed via DIV (Data-in-Virtual) or memory mapping.
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Q: What is COLLATING SEQUENCE?
Answer:
PROGRAM COLLATING SEQUENCE IS sequence-name. Affects comparisons and SORT order. Define custom alphabet in SPECIAL-NAMES. Standard is NATIVE (EBCDIC). ASCII for ASCII order. STANDARD-1 for ASCII collating.
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Q: What is DEFINE MODEL?
Answer:
MODEL copies attributes from existing cluster. DEFINE CLUSTER(NAME(new) MODEL(existing)). Only copies definition, not data. Useful for creating similar clusters. Can override specific parameters.
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Q: Explain ALPHABET clause
Answer:
ALPHABET defines custom collating sequence. ALPHABET MY-SEQ IS 'A' THRU 'Z' 'a' THRU 'z'. Or ALPHABET ASCII IS STANDARD-1. Use with COLLATING SEQUENCE. Affects string comparisons and SORT. Define in SPECIAL-NAMES.
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Q: What is TALLY special register?
Answer:
TALLY is predefined counter for EXAMINE (obsolete verb). Some code still references it. INSPECT replaced EXAMINE. Not recommended for new code. TALLY is global, can conflict. Define your own counters instead.
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Q: What is ORDERED attribute?
Answer:
ORDERED on DEFINE allocates volumes in specified order. Without ORDERED, system chooses. ORDERED ensures predictable allocation. May be important for performance tuning.
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Q: What is CONTROLINTERVALSIZE?
Answer:
CONTROLINTERVALSIZE sets CI size explicitly. CONTROLINTERVALSIZE(4096). Powers of 2, max 32768. Let system default usually. Larger CI better sequential, worse random. Match to workload.
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Q: What is CATALOG vs CATACB?
Answer:
CATALOG parameter specifies which catalog to use. CATALOG(catalog.name) on DEFINE. CATACB no longer used. Modern systems use aliases to route to correct catalog.
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Q: What causes S322 abend?
Answer:
S322 is job/step time exceeded. Check TIME parameter on JOB/EXEC. Causes: infinite loop, too much data, insufficient time allocated. Fix: increase TIME, optimize program, check data volumes. TIME=1440 is no limit (24 hours).
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Q: How to access VSAM via CICS?
Answer:
Define FILE in CICS FCT (File Control Table). Or RDO DEFINE FILE. EXEC CICS READ FILE. VSAM must be closed to batch when CICS owns. NSRV or LSR buffering. BROWSE for sequential.
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Q: Explain SMS-managed storage
Answer:
SMS (Storage Management Subsystem) manages dataset placement. Specify STORCLAS, MGMTCLAS, DATACLAS in DD. DATACLAS sets DCB attributes, STORCLAS controls placement, MGMTCLAS defines retention. SMS uses ACS routines for assignment.
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Q: What is LSR?
Answer:
LSR (Local Shared Resources) pool shares buffers across VSAM files. Efficient memory use. MACRF=LSR in JCL or ACB. CICS uses LSR. Define pool with BLDVRP macro.
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Q: How does IEBCOPY work?
Answer:
IEBCOPY copies/merges PDS members. SYSUT1=input PDS, SYSUT2=output PDS. SYSIN: COPY OUTDD=SYSUT2,INDD=SYSUT1 copies all. SELECT MEMBER=name for specific members. REPLACE option overwrites existing. Can compress PDS.
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Q: Explain RESTART parameter
Answer:
RESTART=stepname restarts job at specified step. RESTART=(stepname,checkid) for checkpointed restart. Use after abend to continue from failure point. Prior steps skipped. Data must be recoverable or recreatable.
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Q: How to monitor VSAM performance?
Answer:
SMF records for I/O counts. LISTCAT for statistics (READS, WRITES, SPLITS). RMF reports. Third-party tools. Track CI/CA splits, EXCP counts, buffer hit ratios.
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Q: What causes S913 abend?
Answer:
S913 is security violation. Not authorized to dataset or resource. Check: RACF/ACF2/TopSecret permissions, dataset profile, user authority level. S913-38 means insufficient access. Contact security administrator.
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Q: How to SEND MAP to terminal?
Answer:
EXEC CICS SEND MAP(mapname) MAPSET(mapsetname) FROM(symbolic-map) ERASE. CURSOR option positions cursor. FREEKB unlocks keyboard. ALARM sounds alarm. MAPONLY sends without data. DATAONLY sends only modified fields.
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Q: What is RECEIVE MAP?
Answer:
EXEC CICS RECEIVE MAP(name) MAPSET(mapset) INTO(symbolic-map). Gets terminal input. Modified fields only (MDT). Check EIBAID for key pressed. MAPFAIL if no data. Symbolic map populated with input.
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Q: What is UNIT parameter?
Answer:
UNIT specifies device type. UNIT=SYSDA (direct access), UNIT=TAPE, UNIT=3390. UNIT=AFF=ddname shares device. UNIT=(SYSDA,2) allocates 2 volumes. SMS may override. UNIT=VIO for virtual I/O (memory only).
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Q: How to handle MAPFAIL?
Answer:
MAPFAIL occurs when RECEIVE MAP finds no modified data. Handle: EXEC CICS RECEIVE MAP ... RESP(resp). IF resp = DFHRESP(MAPFAIL). User pressed Enter without typing. May need to redisplay or handle appropriately.
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Q: Explain JES2 control cards
Answer:
JES2 cards start with /*. /*JOBPARM limits resources. /*ROUTE sends output. /*OUTPUT JESDS specifies JES output. /*PRIORITY sets priority. Process by JES2, not passed to job. Position after JOB card before first EXEC.
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Q: What is ASSIGN command?
Answer:
ASSIGN retrieves system values. EXEC CICS ASSIGN USERID(ws-user) FACILITY(ws-term). Other options: SYSID, ABCODE, PROGRAM. Gets runtime environment info. Useful for audit, conditional processing.
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Q: Explain START command
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START schedules transaction for later. EXEC CICS START TRANSID(trans) AFTER HOURS(1) FROM(data). INTERVAL or TIME for specific time. Data passed in channel/container or FROM/LENGTH. Background processing.
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Q: What is GETMAIN?
Answer:
GETMAIN allocates temporary storage. EXEC CICS GETMAIN SET(pointer) LENGTH(size) INITIMG(X'00'). Returns pointer. Use for dynamic memory. FREEMAIN releases. SHARED for multi-task access. Automatic cleanup on task end.
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Q: What is VOL parameter?
Answer:
VOL specifies volume. VOL=SER=PACK01 specific volume. VOL=REF=*.STEP.DD copies volume from previous. VOL=(,RETAIN) keeps volume mounted. VOL=(,,,5) allows 5 volumes. SER overrides SMS placement. Use cautiously.
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Q: Explain LIKE parameter
Answer:
LIKE copies DCB attributes from existing dataset. DCB=*.STEP1.DD or LIKE=catalog.dataset. Simplifies JCL. Model dataset must exist or be allocated earlier. Override specific attributes: DCB=(LIKE=...,LRECL=100).
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Q: What is transient data?
Answer:
TD queues for sequential I/O. EXEC CICS WRITEQ TD QUEUE(name) FROM(data). Intrapartition for CICS internal. Extrapartition for external datasets. Defined in DCT. Automatic trigger level option.
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Q: What is DFSMS?
Answer:
DFSMS (Data Facility Storage Management Subsystem) automates storage management. Components: SMS, HSM (migration), DFRMM (tape). ACS routines assign classes. Reduces JCL complexity. DATACLAS defines data characteristics.
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Q: Explain HANDLE CONDITION
Answer:
HANDLE CONDITION sets error label. EXEC CICS HANDLE CONDITION NOTFND(para-notfnd). Jumps to label on condition. PUSH/POP HANDLE for nesting. Obsolete - prefer RESP option. Still seen in old code.
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Q: What is HANDLE ABEND?
Answer:
HANDLE ABEND traps abends. EXEC CICS HANDLE ABEND PROGRAM(abend-prog) or LABEL(abend-para). Allows cleanup before termination. CANCEL removes handler. Use for graceful error handling.
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Q: Explain REWRITE command
Answer:
REWRITE updates record. Must READ with UPDATE first. EXEC CICS REWRITE FILE(name) FROM(data) LENGTH(len). Changes record held from READ. Cannot change key. TOKEN matches UPDATE-READ.
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Q: What is DELETE command?
Answer:
DELETE removes record. EXEC CICS DELETE FILE(name) RIDFLD(key). Or after READ UPDATE: DELETE FILE(name). KEYLENGTH/GENERIC for range delete. NOTFND if key missing. NUMREC returns count deleted.
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Q: Explain DD SYSOUT statement
Answer:
SYSOUT=class routes output to JES spool. SYSOUT=* uses MSGCLASS from JOB. SYSOUT=A specific class. Additional: COPIES=2, DEST=node.userid, FCB=fcb-name. Held output: HOLD=YES. OUTPUT statement for complex options.
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Q: Explain RETURN command
Answer:
RETURN ends program or task. EXEC CICS RETURN returns to caller. EXEC CICS RETURN TRANSID(next) COMMAREA(data) for pseudo-conv. IMMEDIATE for no COMMAREA. End of logical unit.
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Q: What is CEDA?
Answer:
CEDA defines CICS resources online. CEDA DEFINE PROGRAM(pgm) GROUP(grp). Resources: TRANSACTION, PROGRAM, FILE, etc. CEDA INSTALL activates. CEDA VIEW displays. RDO (Resource Definition Online).
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Q: What is SET command?
Answer:
SET modifies resource state. EXEC CICS SET FILE(name) OPEN/CLOSED. SET TRANSACTION ENABLED/DISABLED. Requires authority. Dynamic resource management. Change status without CEDA.
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Q: What is KEYLEN parameter?
Answer:
KEYLEN specifies key length for new dataset. DCB parameter for VSAM-like. Or VSAM DEFINE CLUSTER KEYS(length offset). Length 1-255. Required for indexed organization. Offset from 0 or 1 depending on context.
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Q: How to handle multivolume datasets?
Answer:
VOL=(,,,n) allows n volumes. SPACE with volume count. SMS handles multivolume automatically. DISP=MOD extends to new volume. DATACLAS can specify multivolume. Large datasets need multivolume planning.
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Q: What is MRO?
Answer:
MRO (Multi-Region Operation) connects CICS regions. Function shipping sends requests to owning region. Transaction routing sends terminal to AOR. DPL (Distributed Program Link) for remote LINK.
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Q: Explain LABEL parameter
Answer:
LABEL=(n,type) specifies tape label info. n=file sequence number. Type: SL=standard, NL=no labels, SUL=standard user. LABEL=(2,SL) is second file on standard label tape. EXPDT/RETPD for retention.
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Q: What is RETPD parameter?
Answer:
RETPD=nnn specifies retention days. Cannot delete until expired. EXPDT=yyddd for specific date. EXPDT=99365 or RETPD=9999 for permanent. Security software may override. Affects tape and disk datasets.
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Q: Explain recoverable resources
Answer:
Recoverable resources participate in syncpoint. File with RECOVERY(YES). TS MAIN with AUX. Changes backed out on rollback. Non-recoverable not protected. Define appropriate for data.
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Q: What is CEDF?
Answer:
CEDF is execution diagnostic facility. Debug tool. CEDF ON intercepts EXEC CICS. Step through commands. Display/modify data. Powerful debugging. CEDF transaction-id starts debug.
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Q: What is AMP parameter?
Answer:
AMP specifies VSAM buffer parameters. AMP='BUFNI=8,BUFND=4' for index/data buffers. AMP='AMORG' for VSAM organization. OPTCD for options. Overrides VSAM cluster definitions for this run. Affects performance.
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Q: Explain RRN in CICS
Answer:
RRN (Relative Record Number) for RRDS files. RIDFLD contains RRN, not key. Numeric 1-based slot number. RRN option on file commands. Access by position not content.
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Q: What is journaling in CICS?
Answer:
Journaling records activity. EXEC CICS JOURNAL JFILEID(id) FROM(data). For recovery, audit. Define journal file. Can be automatic or explicit. System journal for CICS recovery.
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Q: What is BIF DEEDIT?
Answer:
BIF DEEDIT removes edit characters. EXEC CICS BIF DEEDIT FIELD(data) LENGTH(len). Converts edited numeric to raw. Removes $, commas, etc. Useful for BMS numeric input.
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Q: Explain ASKTIME ABSTIME
Answer:
ABSTIME is packed decimal timestamp. Microseconds since 1/1/1900. ASKTIME returns current. FORMATTIME converts to readable. Use for calculations, comparisons. Full precision timing.
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Q: Explain CICS RECEIVE without MAP
Answer:
RECEIVE INTO without MAP gets raw terminal data. EXEC CICS RECEIVE INTO(area) LENGTH(len). For non-BMS screens. AID in EIBAID. Raw data stream. Lower level than BMS.
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Q: What is MAPONLY?
Answer:
MAPONLY sends map without data. EXEC CICS SEND MAP MAPONLY. Displays initial screen. No symbolic map data. Fast initial display. Use when no data to populate.
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Q: What is MGMTCLAS parameter?
Answer:
MGMTCLAS assigns SMS management class. Controls migration, backup, retention. MGMTCLAS=classname. Defines data lifecycle. HSM uses management class. Installation-defined policies.
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Q: What is PAGING option?
Answer:
PAGING breaks large output. EXEC CICS SEND MAP PAGING. User navigates pages. Autopaging available. Terminal paging commands. For long reports on screen.
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Q: How to use MODIFY parameter?
Answer:
MODIFY references FCB image. MODIFY=(fcb,trc) on OUTPUT. FCB controls forms. TRC is table reference character. For print formatting. Installation-defined FCBs. Used with special forms.
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Q: What is CONVERSE?
Answer:
CONVERSE combines SEND and RECEIVE. EXEC CICS CONVERSE FROM(out) INTO(in). One command for both. Simpler for simple screens. Less control than separate commands.
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Q: What is LENGERR?
Answer:
LENGERR is length error. Data too large for area, or length specification wrong. Check LENGTH values. Common on RECEIVE. Ensure adequate receiving field.
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Q: What is DOCUMENT?
Answer:
DOCUMENT builds dynamic content. CREATE, SET, INSERT commands. For web responses. Template-based output. Modern CICS web support. Replace BMS for web.
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Q: Explain CICS web support
Answer:
CICS handles HTTP. EXEC CICS WEB READ/WRITE. URIMAP defines URLs. Programs handle requests. JSON/XML responses. Modern application interface.
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Q: How to use DOCTEMPLATE?
Answer:
DOCTEMPLATE defines dynamic content. Create template with symbols. Insert data at runtime. EXEC CICS DOCUMENT SET/INSERT. For generating responses.
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Q: What is CICS asynchronous processing?
Answer:
RUN TRANSID for async execution. EXEC CICS RUN TRANSID(xx) CHILD. FETCH CHILD waits for completion. Modern async pattern. Alternative to START.
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Q: How to handle CICS security?
Answer:
RACF/ACF2 integration. EXEC CICS QUERY SECURITY. SIGNON establishes identity. VERIFY checks resource access. XFCT/XPPT exits. Secure by default.
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Q: What is CATALOG parameter in DEFINE?
Answer:
CATALOG(catalog.name) specifies which catalog to use. Without it, uses alias routing. Important for multi-catalog environments. Modern systems often rely on alias. Explicit better for clarity.
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Q: What is DB2 buffer pool?
Answer:
Buffer pool caches data/index pages in memory. BP0, BP1, etc. Hit ratio critical for performance. GETPAGE vs SYNCIO shows effectiveness. Size appropriately. Virtual buffer pool for each pool. Monitor with statistics.
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Q: What is REUSE option purpose?
Answer:
REUSE allows OPEN OUTPUT to reset file. Like delete/define without overhead. Good for work files. DEFINE CLUSTER ... REUSE. Cannot be UNIQUE. Efficient for scratch files.
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Q: How to use PUSH/POP HANDLE?
Answer:
PUSH HANDLE saves current handlers. POP HANDLE restores. EXEC CICS PUSH HANDLE. Allows nested handler management. Clean up with POP. For modular code.
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Q: Explain CICS event processing
Answer:
CICS events for complex situations. WAIT EVENT for multiple conditions. Posted externally. WAIT EXTERNAL alternative. Modern: EVENT binding for async.
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Q: What is CICS resource protection?
Answer:
Protection via RACF/external security. SEC=YES on region. QUERY SECURITY for checks. SECLABEL for levels. Program security attributes.
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Q: What is EXEC CICS SPOOLOPEN?
Answer:
SPOOLOPEN accesses JES spool. SPOOLREAD/SPOOLWRITE for data. SPOOLCLOSE ends. Process job output. Modern batch integration. Requires authorization.
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Q: Explain CICS global user exit
Answer:
Global exits intercept system events. XPPT for program load. XFCT for file operations. Customize CICS behavior. Assembled exits. Powerful but complex.
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Q: What is MERGE statement?
Answer:
MERGE updates or inserts conditionally. MERGE INTO target USING source ON condition WHEN MATCHED THEN UPDATE WHEN NOT MATCHED THEN INSERT. Combines INSERT/UPDATE logic. Efficient for sync operations.
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Q: What is CICS FEPI?
Answer:
FEPI (Front End Programming Interface) connects to external systems. Terminal emulation. Legacy integration. EXEC CICS FEPI commands. Complex configuration.