👁 0
Q: What is the difference between COND and IF/THEN/ELSE in JCL?
Answer:
COND Parameter:
- Tests return codes from previous steps
- Bypasses step if condition is TRUE
- Works opposite to programming logic!
- COND=(4,LT) means: Skip if 4 < any previous RC
IF/THEN/ELSE:
- More intuitive programming-like syntax
- Executes steps when condition is TRUE
- Supports AND, OR operators
- Can check ABEND conditions
Example:
// Using COND (skip if RC < 4) //STEP2 EXEC PGM=PROG2,COND=(4,LT) // Using IF/THEN/ELSE // IF STEP1.RC = 0 THEN //STEP2 EXEC PGM=PROG2 // ELSE //ERROR EXEC PGM=ERRPROC // ENDIF
👁 0
Q: What is 88-level condition name?
Answer:
88-level defines condition names for field values. 01 WS-STATUS PIC X. 88 VALID-STATUS VALUE 'Y'. 88 INVALID-STATUS VALUE 'N'. Use in IF: IF VALID-STATUS. Set using SET VALID-STATUS TO TRUE. Makes code self-documenting.
👁 0
Q: How to use CONTINUE statement?
Answer:
CONTINUE is a no-operation placeholder. Useful in EVALUATE when certain conditions need no action: WHEN 'X' CONTINUE. In IF: IF condition CONTINUE ELSE action. Maintains structure without dummy statements. Not a GOTO target.
👁 0
Q: Explain START statement for VSAM
Answer:
START positions for sequential READ. START filename KEY IS EQUAL/GREATER/NOT LESS THAN key-field. After successful START, READ NEXT retrieves records sequentially from that position. INVALID KEY handles not-found condition.
👁 0
Q: How to handle SQLCODE 100?
Answer:
SQLCODE 100 means not found or end of data. For SELECT INTO: no matching row. For FETCH: no more rows. For UPDATE/DELETE: no rows affected. Check context - may be normal condition, not error.
👁 0
Q: What is alternate index?
Answer:
AIX provides secondary access path. DEFINE AIX over base cluster. Different key. DEFINE PATH to access. BLDINDEX populates. UPGRADE option maintains AIX on base updates. Multiple AIX per cluster.
👁 0
Q: What is USE BEFORE REPORTING?
Answer:
In Report Writer, USE BEFORE REPORTING procedure runs before printing. USE BEFORE REPORTING report-group-name. Allows dynamic modification of report data. Can suppress or modify lines based on runtime conditions.
👁 0
Q: How to extend VSAM file?
Answer:
ALTER ds.name ADDVOLUMES(vol). Or secondary allocation triggers extension. RECORDS/CYLINDERS secondary amount. Up to 255 extents per volume. May need to reorganize if fragmented.
👁 0
Q: What is the difference between COND and IF/THEN/ELSE?
Answer:
COND tests return codes to skip steps (negative logic - skips IF true). IF/THEN/ELSE tests conditions to execute steps (positive logic). IF supports complex expressions, COND is simpler but confusing. IF preferred for readability. COND on JOB affects all steps; on EXEC affects that step.
👁 0
Q: Explain SPACE parameter options
Answer:
SPACE=(unit,(primary,secondary,directory)). Unit: TRK/CYL/block-size. Primary allocated first, secondary in 15 increments. Directory only for PDS. RLSE releases unused. CONTIG requires contiguous. Example: SPACE=(CYL,(10,5,20),RLSE)
👁 0
Q: What is COND CODE?
Answer:
Programs return condition/return code in register 15. COND parameter tests: COND=(4,LT) skips if 4 < any prior return code. Values 0-4095. Convention: 0=success, 4=warning, 8=error, 12+=severe. Used for job flow control.
👁 0
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.
👁 0
Q: How to check job status?
Answer:
SDSF DA/ST panels show jobs. TSO STATUS command. JES2 J'jobname'. JESMSGLG shows JCL, allocation. JESYSMSG has error details. Return code in JESMSGLG. Condition codes per step. Check SYSOUT for program output.
👁 0
Q: Explain generation data groups
Answer:
GDG maintains versions. Base defined with IDCAMS: DEFINE GDG NAME(base) LIMIT(10) SCRATCH. Reference: base(+1) new, base(0) current, base(-1) previous. LIMIT controls kept generations. NOEMPTY/EMPTY for empty condition.
👁 0
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.
👁 0
Q: How to use //IF statement?
Answer:
//IF (condition) THEN executes following steps if true. Conditions: RC, ABEND, ABENDCC, RUN, STEP.RC. Example: //IF (STEP1.RC = 0) THEN ... //ENDIF. Can nest. ELSE available. Clearer than COND parameter.
👁 0
Q: Explain EIBRESP values
Answer:
EIBRESP holds response code. 0=NORMAL. Non-zero indicates condition. Use DFHRESP(condition) for comparison. Common: DFHRESP(NOTFND), DFHRESP(DUPKEY), DFHRESP(INVREQ). Check documentation.
👁 0
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.
👁 0
Q: What is DFHRESP?
Answer:
DFHRESP macro converts response name. DFHRESP(NOTFND) returns numeric value. Use in IF: IF ws-resp = DFHRESP(NORMAL). Readable condition checking. Standard practice.
👁 0
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.
👁 0
Q: What is RLSE subparameter?
Answer:
RLSE releases unused space at close. SPACE=(CYL,(10,5),RLSE). Returns unused secondary allocations. Good practice for new datasets. Saves disk space. May cause allocation issues if reextended.
👁 0
Q: Explain INVREQ condition
Answer:
INVREQ is invalid request. Command invalid for situation. Check: command syntax, option combinations, resource state. EIBRESP2 may have more info. Common programming error.
👁 0
Q: What is clustered index?
Answer:
Clustered index determines physical row order. Only one per table. Other indexes are secondary. CLUSTER keyword on CREATE INDEX. Good for range queries on cluster key. REORG restores clustering after updates.
👁 0
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.
👁 0
Q: Explain UPDATE with JOIN
Answer:
UPDATE table SET col = value FROM table t1 INNER JOIN table t2 ON... WHERE condition. Or: UPDATE t1 SET col = (SELECT col FROM t2 WHERE t2.key = t1.key). Merge statement is alternative.
👁 0
Q: How to delete with JOIN?
Answer:
DELETE FROM table WHERE key IN (SELECT key FROM other WHERE condition). Or: DELETE FROM t1 WHERE EXISTS (SELECT 1 FROM t2 WHERE t1.key = t2.key). Correlated subquery common for conditional delete.
👁 0
Q: What is INSERT...SELECT?
Answer:
INSERT INTO table SELECT cols FROM other_table WHERE condition. Bulk insert from query. Column count/types must match. Faster than row-by-row. Can transform data during insert. Good for data migration.
👁 0
Q: What is EVALUATE statement and when to use it?
Answer:
EVALUATE is COBOL's case/switch construct. Syntax: EVALUATE TRUE WHEN condition-1 statement WHEN OTHER default END-EVALUATE. More readable than nested IF for multiple conditions. Can evaluate multiple subjects and use THRU for ranges.
👁 0
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.
👁 0
Q: Explain ALTERNATE RECORD KEY
Answer:
ALTERNATE RECORD KEY defines secondary indexes for INDEXED files. SELECT file-name ALTERNATE RECORD KEY IS ALT-KEY WITH DUPLICATES. Allows access by multiple keys. DUPLICATES permits non-unique values. Define path in VSAM cluster.
👁 0
Q: What is ON SIZE ERROR?
Answer:
ON SIZE ERROR traps arithmetic overflow. COMPUTE X = A + B ON SIZE ERROR PERFORM error-handler END-COMPUTE. Also NOT ON SIZE ERROR for success. Must be enabled (TRUNC option). Prevents abends from overflow conditions.
👁 0
Q: What is OPTIONAL file clause?
Answer:
OPTIONAL allows missing files: SELECT OPTIONAL input-file. OPEN succeeds even if file absent. READ immediately gets end-of-file. Useful for conditional processing. FILE STATUS 35 if accessed without OPTIONAL.
👁 0
Q: Explain condition-name SET TRUE
Answer:
SET condition-name TO TRUE assigns the condition's VALUE. If 88 ACTIVE VALUE 'A', SET ACTIVE TO TRUE moves 'A' to parent. Cleaner than MOVE 'A' TO STATUS. Makes code self-documenting. Multiple values take first.
👁 0
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.
👁 0
Q: How to resize VSAM?
Answer:
Cannot resize directly. REPRO out, DELETE, DEFINE larger, REPRO back. Or ALTER to add secondary space/volumes. Planning important - define adequate size initially.
👁 0
Q: How to use IDCAMS conditionally?
Answer:
IF LASTCC/MAXCC condition THEN command. Example: IF MAXCC < 8 THEN REPRO... SET MAXCC/LASTCC resets codes. Allows conditional processing in IDCAMS job steps.
👁 0
Q: What is IDCAMS utility?
Answer:
IDCAMS manages VSAM and catalog. Commands: DEFINE CLUSTER, DELETE, REPRO, LISTCAT, ALTER, PRINT. //SYSIN DD * has commands. REPRO copies VSAM files. DEFINE creates VSAM clusters. IF/THEN/ELSE for conditional processing.
👁 0
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.
👁 0
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.
👁 0
Q: How to handle NOTFND condition?
Answer:
NOTFND means record not found. Check RESP: IF ws-resp = DFHRESP(NOTFND). Or HANDLE CONDITION NOTFND(para). Common for READ/DELETE. Handle gracefully - display message, take action.
👁 0
Q: What causes S837 abend?
Answer:
S837 is end of volume and no more volumes available. Dataset needs more space. Solutions: allocate larger primary/secondary, increase volume count, extend dataset. IEFBR14 can extend with MOD DISP.
👁 0
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.
👁 0
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.
👁 0
Q: What is MAPFAIL condition?
Answer:
MAPFAIL when RECEIVE MAP gets no data. Terminal timeout or clear. Handle: check RESP for DFHRESP(MAPFAIL). May need to resend map or handle timeout.
👁 0
Q: Explain DEFINE PATH for VSAM?
Answer:
PATH provides alternate access to VSAM cluster via alternate index. IDCAMS: DEFINE PATH NAME(path.name) PATHENTRY(aix.name). Reference PATH in JCL, not AIX directly. Allows secondary key access.
👁 0
Q: Explain ITEMERR condition
Answer:
ITEMERR is item error in TS. Item number invalid. Out of range or doesn't exist. ITEM 1 is first. Check NUMITEMS. Common in READQ TS.
👁 0
Q: What is CASE expression?
Answer:
CASE provides if-then logic. CASE WHEN cond1 THEN val1 WHEN cond2 THEN val2 ELSE default END. Simple CASE: CASE col WHEN 'A' THEN 'Active' END. Use in SELECT, WHERE, ORDER BY. Powerful for transformations.
👁 0
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.
👁 0
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.