1. What is primary allocation for a Data Set?
The space allocated when the Data Set is first created
2. What is the difference between primary and secondary allocations for a Data Set?
Secondary allocation is done when more space is required than what has already been allocated
3. How many extents are possible for a Sequential File? For a VSAM File ?
16 extents on a volume for a Sequential File and 123 for a VSAM File
4. What does a disposition of (NEW, CATLG, DELETE) mean? -
That this is a new Data Set and needs to be allocated, to CATLG the Data Set if the step is successful and to delete the Data Set if the step abends.
5. What does a disposition of (NEW, CATLG, KEEP) mean? -
That this is a new Data Set and needs to be allocated, to CATLG the Data Set if the step is successful and to KEEP but not CATLG the Data Set if the step abends Thus if the step abends, the Data Set would not be catalogued and we would need to supply the Vol ser the next time we refer to it
6. How do you access a File that had a disposition of KEEP? -
Need to supply volume serial no VOL=SER=xxxx MOD, DELETE
7. What does a disposition of (, DELETE) mean?
The MOD will cause the Data Set to be created (if it does not exist), and then the two DELETE will cause the Data Set to be deleted whether the step abends or not this disposition is used to clear out a Data Set at the beginning of a job
8. What is the DD statement for an output File?
Unless allocated earlier, will have the following parameters:
DISP=(NEW, CATLG, DELETE), UNIT, SPACE & DCB
9. What do you do if you do not want to keep all the space allocated to a Data Set?
Specify the parameter RLSE (release) in the SPACE.
E.g.: SPACE=(CYL, (50,50), RLSE)
10. What is DISP=(NEW, PASS, DELETE)?
This is a new File and create it, if the step terminates normally, pass it to the subsequent steps and if step abends, delete it This Data Set will not exist beyond the JCL
11. How do you create a temporary Data Set? Where will you use them?
Temporary Data Sets can be created either by not specifying any DSNAME or by specifying the temporary File indicator as in DSN=&&TEMP
We use them to carry the output of one step to another step in the same job The Data Set will not be retained once the job completes
12. How do you restart a proc from a particular step?
In job card, specify RESTART=proc step step name where procstep = name of the JCL step that invoked the proc and step name = name of the proc step where you want execution to start
13. How do you skip a particular step in a proc/JOB?
Can use either condition codes or use the jcl control statement IF (only in ESA JCL)
14. A PROC has five steps Step 3 has a condition code how can you override/nullify this condition code?
Provide the override on the EXEC stmt in the JCL as follows:
//STEP001 EXEC procname, CONDstepname=value
All parameters on an EXEC stmt in the proc such as COND, PARM have to be overridden like this
15. How do you override a specific DDNAME/SYSIN in PROC from a JCL?
//<Stepnamedd> DSN=
16. What is NOTCAT 2?
This is an MVS message indicating that a duplicate catalog entry exists E.g., if you already have a Data Set with dsn = 'xxxxyyyy' and u try to create one with disp new, catlg, you would get this error the program open and write would go through and at the end of the step the system would try to put it in the system catalog at this point since an entry already exists the catlg would fail and give this message you can fix the problem by deleting/uncataloging the first data set and going to the volume where the new Data Set exists(this info is in the msglog of the job) and cataloging it
17. What is 'S0C7' ABEND?
Caused by invalid data in a numeric field
18. What is a S0C4 error?
Storage violation error - can be due to various reasons e.g.: READING a File that is not open, invalid address referenced due to subscript error
19. What are SD37, SB37, and SE37 abends?
All indicate Data Set out of space. SD37 - no secondary allocation was specified. SB37 - end of vol and no further volumes specified. SE37 - Max of 16 extents already allocated
20. What is S322 ABEND?
Indicates a time out ABEND Your program has taken more CPU time than the default limit for the job class could indicate an infinite loop
21. Why do you want to specify the REGION parameter in a JCL step?
To override the REGION defined at the JOB card level
REGION specifies the max region size REGION=0K or 0M or omitting REGION means no limit will be applied
22. What does the TIME parameter signify? What does TIME=1440 mean?
TIME parameter can be used to overcome S322 abends for programs that genuinely need more CPU time TIME=1440 means no CPU time limit is to be applied to this step
23. What is COND=EVEN?
Means execute this step even if any of the previous steps, terminated abnormally
24. What is COND=ONLY?
Means execute this step only if any of the previous steps, terminated abnormally
25. How do you check the syntax of a JCL without running it?
TYPERUN=SCAN on the JOB card or use JSCAN
26. What does IEBGENER do?
Used to copy one SAM File to another Source Data Set should be described using SYSUT1 ddname Destination Data Set should be described using SYSUT2 IEBGENR can also do some reformatting of data by supplying control cards via SYSIN
27. How do you send the output of a COBOL program to a member of a PDS?
Code the DSN as pds (member) with a DISP of SHR The DISP applies to the pds and not to a specific member
28. I have multiple jobs (JCLs with several JOB cards) in a member what
Happens if I submit it?
Multiple jobs are submitted (as many jobs as the number of JOB cards)
29. I have a COBOL program that ACCEPT some input data how do you code the JCL statement for this? (How do you code in stream data in a JCL?)
//SYSIN DD*
Input data
Input data
/*
30. Can you code instream data in a PROC ?
No
31. How do you overcome this limitation?
One way is to code SYSIN DD DUMMY in the PROC, and then override this from the JCL with instream data
32. How do you run a COBOL batch program from a JCL? How do you run a
COBOL/DB2 program?
To run a non DB2 program,
//STEP001 EXEC PGM=MYPROG
To run a DB2 program,
//STEP001 EXEC PGM=IKJEFT01
//SYSTSIN DD *
DSN SYSTEM ()
RUN PROGRAM (MYPROG)
PLAN () LIB () PARMS ()
/*
33. What is STEPLIB, JOBLIB? What is it used for?
Specifies that the private library (or libraries) specified should be searched before the default system libraries in order to locate a program to be executed
STEPLIB applies only to the particular step, JOBLIB to all steps in the job
34. What is order of searching of the libraries in a JCL?
First any private libraries as specified in the STEPLIB or JOBLIB, then the system libraries such as SYS1LINKLIB the system libraries are specified in the link list
35. What happens if both JOBLIB & STEPLIB is specified?
JOBLIB is ignored
36. When you specify multiple Data Sets in a JOBLIB or STEPLIB, what factor
Determines the order?
The library with the largest block size should be the first one
37. How to change default proclib?
//ABCD JCLLIB ORDER=(MEMYPROCLIB, SYS1PROCLIB)
38. The DISP in the JCL is MOD and the program opens the File in OUTPUT mode what happens? The DISP in the JCL is SHR and the pgm opens the File in EXTEND mode what happens?
Records will be written to end of File (append) when a WRITE is done in both cases
39. What are the valid DSORG values?
PS - SAM, PO - Partitioned, IS - ISAM
40. What are the differences between JES2 & JES3?
JES3 allocates Data Sets for all the steps before the job is scheduled. In JES2, allocation of Data Sets required by a step is done only just before the step executes.
JOB /EXEC/DD ALL PARAMETERS
JOBLIB/STEPLIB
PROCEDURES, PARAMETERS PASSING
CONDITION VARIABLES
ABEND CODES.
41. What are the kinds of job control statements?
The JOB, EXEC and DD statement
42. What is the meaning of keyword in JCL? What is its opposite?
A keyword in a JCL statement may appear in different places and is recognized by its
Name, eg MSGCLASS in the JOB statement The opposite is positional words, where
their meaning is based on their position in the statement, eg in the DISP keyword the
=(NEW, CATLG, DELETE) meaning are based on first, second and third position.
43. Describe the JOB statement, its meaning, syntax and significant keywords.
The JOB statement is the first in a JCL stream its format is //
Job name, keyword JOB, accounting information in brackets and keywords,
MSGCLASS, MSGLEVEL, NOTIFIY, CLASS, etc.
44. Describe the EXEC statement, its meaning, syntax and keywords.
The EXEC statement identifies the program to be executed via a
PGM=program name keyword its format is //jobname EXEC PGM=program name
The PARM= keyword can be used to pass external values to the executing program.
45. Describe the DD statement, its meaning, syntax and keywords.
The DD statement links the external Data Set name (DSN) to the DDNAME coded
Within the executing program It links the File names within the program code to the
File names know to the MVS operating system the syntax is // ddname DD
DSN=Data Set name other keywords after DSN are DISP, DCB, SPACE, etc.
46. What is a PROC? What is the difference between an instream and a
Catalogued PROC?
PROC stands for procedure It is 'canned' JCL invoked by a PROC statement an
Instream PROC is presented within the JCL; a catalogued PROC is referenced from
a proclib partitioned Data Set.
47. What is the difference between a symbolic and an override in executing a
PROC?
A symbolic is a PROC placeholder; the value for the symbolic is supplied when the
PROC is invoked, eg &symbol=value An override replaces the PROC's statement
With another one; it substitutes for the entire statement
48. What is RESTART? How is it invoked?
A RESTART is a JOB statement keyword It is used to restart the job at a specified s
step rather than at the beginning
48. What is a GDG? How is it referenced? How is it defined? What is a
MODELDSCB?
GDG stands for generation data group It is a Data Set with versions that can be
referenced absolutely or relatively It is defined by an IDCAMS define generation
data group execution
49. Explain concatenating Data Sets
Data Sets can be grouped in a DD statement one after another, eg in a JOBLIB
statement where the load module can exist in one of many Data Sets.
49. What is the difference between specifying DISP=OLD and DISP=SHR for a Data
Set?
A DISP=OLD denotes exclusive control of the Data Set; DISP=SHR means there is
no exclusivity.
50. What is MOD and when would you use it?
DISP=MOD is used when the Data Set can be extended, ie, you can add records at
the end of an existing Data Set
51. What are the keywords associated with DCB? How can you specify DCB
Information? What is the OS precedence for obtaining that DCB information, ie
Where does the system look for it first?
The keywords associated with the DCB parameter are LRECL, RECFM,
BLKSIZE and DSORG The DCB information can be supplied in the DD statement
The system looks for DCB information in the program code first
52. How do you designate a comment in JCL?
The comment statement is //* followed by the comments.
53. What is the meaning of the EXEC statement keyword, COND? What is its
Syntax?
COND specifies the conditions for executing the subsequent job step the value after
the COND= is compared to the return codes of the preceding steps and if the
comparison is true; the step is bypassed (If this answer confuses you, welcome to
the club - memorizes it and don't ask questions!).
54. What is the improvement to COND= in the latest version of MVS?
MVS now allows for an IF bracketed by an END IF around any job step to replace the
COND= syntax Again, if the IF statement is true, the step is bypassed.
55. What is the purpose of the PARM keyword in the EXEC statement?
The value after the PARM= specifies control information to be passed to the
executing program of the job step
56. What is the purpose and meaning of the REGION keyword and what JCL
statement is it associated with?
REGION specifies the maximum CPU memory allocated for a particular job or job
step If REGION is in the JOB card, it relates to the entire job; if in the EXEC
statement, it relates to the job step.
57. What is the purpose and meaning of the TIME keyword and what JCL
statement is it associated with?
TIME specifies the maximum CPU time allocated for a particular job or job step If
TIME is in the JOB card, it relates to the entire job; if in the EXEC statement, it relates
to the job step.
58. What is the meaning of data definition name (DD name) and Data Set name
(DSN name) in the DD statement?
Data definition name is the eight character designation after the // of the DD
statement It matches the internal name specified in the steps executing program In
COBOL that's the name specified after the ASSIGN in the SELECT ASSIGN
statement Data Set name is the operating system (MVS) name for the File
59. How is the keyword DUMMY used in JCL?
For an output File DUMMY specifies that the output is to be discarded for input it
specifies that the File is empty.
60. What does the keyword DCB mean and what are some of the keywords
associated IT
DCB stands for data control block; it is a keyword for the DD statement used to
describe Data Sets Keywords associated with it are BLKSIZE, DEN, LRECL and
RECFM.
61. What is the difference between BLKSIZE and LRECL?
BLKSIZE specifies the number of bytes
62. What are all the JCL statements used in JCL? & What are the JCL statements you have coded so far?
//JOB marks the beginning of a job, contains job information
//EXEC marks the beginning of a job step, identifies program, cataloged procedure to
be executed
//DD (data definition), identifies a data set and its attributes
//OUTPUT (specifies processing options for system output(sysout) data sets)
//(null) (end of job)
/* (end of data placed in input stream)
//PROC (procedure)
//PEND (procedure end)
//* (comment)
63. What is the difference between the positional parameters & keyword parameters, give examples where they are used?
Positional Parameters are:-
a). Sequence predetermined
b) Parameters separated by commas
c) Omitted parameters must be indicated by two consecutive commas.
d) Installation dependent
EX:
//JOBNAME JOB (DIS, TRG.TRGGLO.NL.BATCH), ‘PGM1)
//SETP01 EXEC PGM=MYPROG
Keyword parameters are Predetermined words are referred to as key word
Parameters. Any sequence is permitted, separated by commas.
Follow positional parameters.
Format is <Keyword parameter> = <value>
EX:
//JOBNAME JOB (DIS, TRG, N1, BATCH), MSGLEVEL=(1,1),
// MSGCLASS=X, NOTIFY=QZ6P03T, TYPRUN=SCAN
64. What are the operands coded in a JOB statement?
All the Positional and Key word parameters in the JOB statement.
Accounting Information, MSGCLASS, CLASS, MSGLEVEL, NOTIFY, USERID,
PASSWD, COND, REGION, RESTART.
65. How many characters can be coded for a job name? What were you coding as a job name?
8 Characters, Usually JOBNAME will be like User-id + 1 Char
66. What is the difference between the Comment statement and the Comments? How they were coded in a JCL?
//* is the comment statement and it starts from column number 1
Anything that is written after 71st column is taken as a comment.
67. How will you check the syntax of the JOB without executing it?
Can use JSCAN.Code TYPRUN=SCAN and submit the JCL for syntactical errors.
68. What are all the parameters needed in a DD statement to create a data set thru JCL? How a Partitioned data set is created thru JCL?
a. DISP (Disposition): The DISP parameter describes the status of a data set to the system, what is to be done with the data set at the end of the job step, and what to do with the data set if the step terminates abnormally
b. DCB (Data control black) :
DCB=(LRECL=NN, BLKZIZE=YY, RECFM=Z, DSORG=MM)
Z can be F, FB, V, VB
MM Can be PS (physical sequence) PO (partitioned)
c. DSN (Data set name):
d. UNIT: Identifies device of data set
e. Space:
69. How is the Catalog procedure called from a JCL, if it is lying in your own data sets?
STEP1 EXEC PROC=PROC1
The library in which PROC1 is present should be mentioned in PROCLIB.
70. What is the difference between the In-stream Procedure & Catalog Procedure?
In-stream Procedures begin with a PROC stmt and must be terminated by a PEND
Stmt. (PEND can also be coded for a cataloged Procedure, but it isn’t required) The
PENC stmt coded as:
//Option-name PEND comments
The In-stream Procedure is placed following the JOB statement of the JOB. Up to 15
In-stream Procedures can be included in a single job. Each In-stream Procedure may
be invoked several times with in the job.
//QZ5P13TD JOB (18636), ‘HARISH’, CLASS=A
//RUN PROC In-stream procedure starts from here
//GO EXEC PGM=ONE
//SYSOUT DD SYSOUT=A
//PEND
//STEP1 EXEC RUN procedure is used like
..
A set of JCL stmt’s consisting of a PROC stmt and one or more EXEC and DD stmt
(steps), which is placed in a procedure library. It executed by an EXEC (procedure)
stmt in another data set (called the execution JCL).
Advantages : Saves time, prevents errors.
71. What is the Symbolic parameter? What for it is needed? Where it is most commonly used?
Any parameter that can vary with each execution is a good candidate for definition of
a symbolic parameter. Use of symbolic parameter make the procedure more flexible.
This prevents the procedure to be modified each and every time a small and
recurring change is needed at a place.
//DD1 DD DSNAME=&SYSUID..PROFILE,DISP=(NEW,KEEP),
72. Can you explain the DISP Parameter in detail? What are the default DISP Parameters?
a. Current Status
NEW – Default
OLD – exclusive
SHR – Simultaneously
MOD –
b. Normal Disposition
KEEP – Default if DISP = SHR, OLD, MOD
DELETE – Default if DISP = NEW
CATLG
c. Abnormal Termination – same as Normal Disposition
73. What is the difference between the Refer-back & Overriding parameters? How
are they coded in a JCL?
Refer back option is a reference to an earlier DD statement in the job or in cataloged
or in in-stream procedure called by a job step.
KEYWORD = reference.
//JOB1 JOB ..
//STEPA EXEC ..
//DD1 DD DSN=REPORT
...
// DD4 DD DSN=*.DD1
//JOB2 JOB ..
//SETP1 EXEC ..
//DDA DD DSN=D578.POL.PUBS01
..
//STEP2 EXEC ..
//DDB DD DSN=*.STEP1.DDA
Over riding parameters.
In an In-stream or Cataloged procedures, the DD names mentioned in the JCL will
override the ones in the procedures.
//JOB1 JOB ..
//STEPA EXEC PROC1
//PS1.DD1 DD DSN=SAMPLE.PUB,DISP=SHR
//PS2.DD2 DD DSN=SAMPLE.PUB1,DISP=SHR
Proc PROC1 contains...
//PS1 EXEC PGM=ABC
//*
//DD1 DD DSN=DUMMY
//SYSOUT DD SYSOUT=*
//
//PS2 EXEC PGM=DEF
//*
//DD1 DD DSN=SAMP.PROG.DATA,DISP=SHR
//DD2 DD DSN=SAMP.PROG.DATA1,DISP=SHR
// SYSOUT DD SYSOUT=*
74. How do you pass parameters to a program coded in an EXEC statement?
Through PARM Clause coded on the EXEC statement. The parameters have to be
defined in the Linkage Section of COBOL program.
75. What is a GDG? How will you create a GDG? Can a GDG be used for Partitioned Data sets ?
A GDG is Generation Data Group. GDG’S allow users to create multiple data sets
with the same base name distinguished by a logical number. History files can be
referenced by using a negative generation number.
GDG base can be created using a utility (IEBPROGM or IDCAMS)
With (+1) we will be creating.
EX: //OUTDD DD DSN=QZ6P03T.ARUN.MASTER(+1) (Create new data set)
//INDD DD DSN=QZ6P03T.ARUN.MASTER(+0) (Reference most current data
set).
Yes - GDG can be sequential, direct, or partitioned Organization and can be reside
on tape or direct-access volumes
GDG must always be cataloged
76. What are the parameters used in creating a GDG? Explain in detail? Can you
alter the parameters for the existing GDG? If yes, How?
Creating a Model Data Set Label (or control block, DSCB) This label is a data set
which contains DCB attributes and is usually referred to in the DCB parameter when
creating new GDG data sets. Most shops create the model DSCB with no DCB
attributes.
77. What for the Model data set used for a GDG? How much space will you give to the Model Data set ?
The system needs an existing data set to serve as a model supplying the DCB
parameters for the GDG to you want to create. The system uses the data set label to
obtain the DCB sub-parameters, and the model is called the DSCB for reasons lost to
history.
Need not specify any space while creating a model data set.
78. How many Maximum generations can be created for a GDG? How will you
create a Generation data set ?
The maximum number of GDG versions that can be created is 255.
A GDG data set is created with “(+1)” appended to the name of the GDG base.
79. What is the E37 error? How will you resolve it with out losing a single byte of data? (Hint: This Error comes when you save the data set after editing it)
Insufficient Space.
80. What is SOC7 abend ? How do you resolve it?
Data Exception. Eliminate the bad data by debugging the program.
