What is primary allocation for a dataset?
The space allocated when the dataset is first created.
What is the difference between primary and secondary allocations for a
dataset?
Secondary allocation is done when more space is required than what has
already been allocated.
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.
What does a disposition of (NEW,CATLG,DELETE) mean?
That this is a new dataset and needs to be allocated, to CATLG the
dataset if the step is successful and to delete the dataset if the step
abends.
What does a disposition of (NEW,CATLG,KEEP) mean?
That this is a new dataset and needs to be allocated, to CATLG the
dataset if the step is successful and to KEEP but not CATLG the dataset
if the step abends. Thus if the step abends, the dataset would not be
catalogued and we would need to supply the vol. ser the next time we
refer to it.
How do you access a file that had a disposition of KEEP?
Need to supply volume serial no. VOL=SER=xxxx.
What does a disposition of (MOD,DELETE,DELETE) mean ?
The MOD will cause the dataset to be created (if it does not exist), and
then the two DELETEs will cause the dataset to be deleted whether the
step abends or not. This disposition is used to clear out a dataset at
the beginning of a job.
What is the DD statement for a output file?
Unless allocated earlier, will have the foll parameters:
DISP=(NEW,CATLG,DELETE), UNIT , SPACE & DCB .
What do you do if you do not want to keep all the space allocated to a
dataset?
Specify the parameter RLSE ( release ) in the SPACE e.g.
SPACE=(CYL,(50,50),RLSE)
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 dataset
will not exist beyond the JCL.
How do you create a temporary dataset? Where will you use them?
Temporary datasets 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 dataset will not be retained once the job completes.
How do you restart a proc from a particular step?
In job card, specify RESTART=procstep.stepname
where procstep = name of the jcl step that invoked the proc
and stepname = name of the proc step where you want execution to start
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)
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,COND.stepname=value
All parameters on an EXEC stmt in the proc such as COND, PARM have to be
overridden like this.
How do you override a specific DDNAME/SYSIN in PROC from a JCL?
//
What is NOTCAT 2 ?
This is an MVS message indicating that a duplicate catalog entry exists.
E.g., if you already have a dataset with dsn = ‘xxxx.yyyy’ 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 dataset exists(this info is in the msglog of the
job) and cataloging it.
What is 'S0C7' abend?
Caused by invalid data in a numeric field.
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.
What are SD37, SB37, SE37 abends?
All indicate dataset 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.
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.
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.
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.
What is COND=EVEN ?
Means execute this step even if any of the previous steps, terminated
abnormally.
What is COND=ONLY ?
Means execute this step only if any of the previous steps, terminated
abnormally.
How do you check the syntax of a JCL without running it?
TYPERUN=SCAN on the JOB card or use JSCAN.
JCL interview questions and answers
