JOB CONTROL LANGUAGE(JCL)


The following are the most Frequently Asked Questions (FAQS) :

Q1) What is a Generation Data Group (GDG)?

A1) Generation Data Group is a group of chronologically or functionally related datasets. GDGs are processed periodically, often by adding a new generation, retaining previous generations, and sometimes discarding the oldest generation.

Q2) How is a GDG base created?

A2) A GDG base is created in the system catalog and keeps track of the generation numbers used for datasets in the group. IDCAMS utility is used to define the GDG base.

Q3) What is model dataset label(Model DSCB)?

A3) A model dataset label is a pattern for the dataset label created for any dataset named as a part of the GDG group. The system needs an existing dataset to serve as a model to supply the DCB parameters for the generation data group one wishes to create. The model dataset label must be cataloged. The model DSCB name is placed on the DCB parameter on the DD statement that creates the generation data group.

Q4) How are GDGs concatenated?

A4) Generation Data Groups are concatenated by specifying each dataset name and the generation number for all generations of the generation data group. Otherwise to have all generations of a generation data group, omit the generation number. The DD statement will refer to all generations. The result is the same as if all individual datasets were concatenated. If generations are not on the same volume, this will not work.

Q5) How is a new GDG coded?

A5) A new GDG is coded as (+1) after the dataset name as follows: DSN=JAN.DATA(+1). This will cause all generations to be pushed down one level at the end of the job.

Q6) When should DISP=MOD is used?

A6) DISP=MOD is used to either extend an existing sequential dataset or to create a dataset if it does not exist. If the dataset exists, then records are appended to the dataset at the end of the existing dataset. If the dataset does not exist, the system treats MOD as if it were NEW, provided that the volume parameter has not been used. If the volume parameter is used, the system terminates the job and does not create the new dataset. MOD can be used to add to a dataset that extends onto several volumes. Always specify a disposition of CATLG with MOD for cataloged datasets, even if they are already cataloged, so that any additional volume serial numbers will be recorded in the catalog.

Q7) How is a dataset passed from one step to another?

A7) A dataset is passed from one step to another based on what is coded on the DISP parameter. The dataset can only be passed to subsequent steps if PASS was used on the disposition parameter.

Q8) How are datasets concatenated?

A8) Datasets are concatenated by writing a normal DD statement for the first dataset and then adding a DD statement without a DDNAME for each dataset to be concatenated in the order they are to be read. The following is an example of three datasets concatenated:

//YEARDAT DD DSN=JAN.DATA,DISP=SHR

// DD DSN=FEB.DATA,DISP=SHR

// DD DSN=MAR.DATA,DISP=SHR

Q9) What is the difference between the JOBLIB and the STEPLIB statements?

A9) The JOBLIB statement is placed after the JOB statement and is effective for all job steps. It cannot be placed in a

cataloged procedure. The STEPLIB statement is placed after the EXEC statement and is effective for that job step

only. Unlike the JOBLIB statement, the STEPLIB can be placed in a cataloged procedure.

Q10) Name some of the JCL statements that are not allowed in procs.?

A10) Some of the JCL statements which are not allowed in procedures are:

1. JOB, Delimiter(/*), or Null statements

2. JOBLIB or JOBCAT DD statements

3. DD * or DATA statements

4. Any JES2 or JES3 control statements

Q11) What is primary allocation for a dataset?

A11) The space allocated when the dataset is first created.

Q12) What is the difference between primary and secondary allocations for a dataset?

A12) Secondary allocation is done when more space is required than what has already been allocated.

Q13) How many extents are possible for a sequential file ? For a VSAM file ?

A13) 16 extents on a volume for a sequential file and 123 for a VSAM file.

Q14) What does a disposition of (NEW,CATLG,DELETE) mean? - GS

A14) 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.

Q15) What does a disposition of (NEW,CATLG,KEEP) mean? - GS

A15) 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.

Q16) How do you access a file that had a disposition of KEEP? - GS

A16) Need to supply Volume Serial Number VOL=SER=xxxx.

Q17) MOD, DELETE; What does a disposition of (,DELETE) mean ?

A17) 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.

Q18) What is the DD statement for a output file?

A18) Unless allocated earlier, will have the following parameters: DISP=(NEW,CATLG,DELETE), UNIT , SPACE & DCB

Q19) What do you do if you do not want to keep all the space allocated to a dataset? - GS

A19) Specify the parameter RLSE ( release ) in the SPACE e.g. SPACE=(CYL,(50,50),RLSE)

Q20) What is DISP= (NEW,PASS,DELETE)?

A20) 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.

Q21) How do you create a temporary dataset? Where will you use them?

A21) 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.

Q22) How do you restart a PROC from a particular step? - GS

A22) 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

Q23) How do you skip a particular step in a proc/JOB? - GS

A23) Can use either condition codes or use the jcl control statement IF (only in ESA JCL)\

Q24) A PROC has five steps. Step 3 has a condition code. How can you override/nullify this condition code? - GS

A24) 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.

Q25) How do you override a specific DDNAME/SYSIN in PROC from a JCL?

A25) // DSN=...

Q26) What is NOTCAT 2 - GS

A26) 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.

Q27) What is 'S0C7' abend? - GS

A27) Caused by invalid data in a numeric field.

Q28) What is a S0C4 error ? - GS

A28) 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.

Q29) What are SD37, SB37, SE37 abends?

A29) 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.

Q30) What is S322 abend ?

A30) 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.

Q31) Why do you want to specify the REGION parameter in a JCL step? - GS

A31) 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.

Q32) What does the TIME parameter signify ? What does TIME=1440 mean ?

A32) 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.

Q33) What is COND=EVEN ?

A33) Means execute this step even if any of the previous steps, terminated abnormally.

Q34) What is COND=ONLY ?

A34) Means execute this step only if any of the previous steps, terminated abnormally.

Q35) How do you check the syntax of a JCL without running it?

A35) TYPERUN=SCAN on the JOB card or use JSCAN.

Q36) What does IEBGENER do?

A36) Used to copy one QSAM file to another. Source dataset should be described using SYSUT1 ddname. Destination dataset should be described using SYSUT2. IEBGENR can also do some reformatting of data by supplying control cards via SYSIN.

Q37) How do you send the output of a COBOL program to a member of a PDS?

A37) Code the DSN as PDS (member) with a DISP = SHR. The DISP applies to the PDS and not to a specific member.

Q38) I have multiple jobs ( JCLs with several JOB cards ) in a member. What happens if I submit it?

A38) Multiple jobs are submitted (as many jobs as the number of JOB cards).

Q39) I have a COBOL program that Accepts some input data. How do you code the JCL statement for this?

( How do you code instream data in a JCL? )

A39) //SYSIN DD*

input data

input data

/*

Q40) Can you code instream data in a PROC ?

A40) No.

Q41) How do you overcome this limitation ?

A41) One way is to code SYSIN DD DUMMY in the PROC, and then override this from the JCL with instream data.

Q42) How do you run a COBOL batch program from a JCL? How do you run a COBOL/DB2 program?

A42) 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(...)

/*

Q43) What is STEPLIB, JOBLIB? What is it used for? - GS

A43) 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.

Q44) What is order of searching of the libraries in a JCL? - GS

A44) First any private libraries as specified in the STEPLIB or JOBLIB, then the system libraries such as SYS1.LINKLIB. The system libraries are specified in the link list.

Q45) What happens if both JOBLIB and STEPLIB is specified ?

A45) JOBLIB is ignored.

Q46) When you specify mutiple datasets in a JOBLIB or STEPLIB, what factor determines the order? - GS

A46) The library with the largest block size should be the first one.

Q47) How to change default PROCLIB?

A47) //ABCD JCLLIB ORDER=(ME.MYPROCLIB,SYS1.PROCLIB)

Q48) 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 program opens the file in EXTEND mode. What happens ?

A48) Records will be written to end of file (append) when a WRITE is done in both cases.

Q49) What are the valid DSORG values ?

A49) PS - QSAM, PO - Partitioned, IS - ISAM

Q50) What are the differences between JES2 & JES3 ?

A50) JES3 allocates datasets for all the steps before the job is scheduled. In JES2, allocation of datasets required by a step are done only just before the step executes.

Q51) What are the causes for S0C1, S0C4, S0C5, S0C7, S0CB abends ?

A51) S0C1-May be due to 1.Missing or misspelled DD name 2.Read/Write to unopened dataset 3.Read to dataset opened

output 4.Write to dataset opened input 5.Called subprogram not found

S0C4-may be due to 1.Missing Select statement(during compile) 2.Bad Subscript/index 3.Protection Exception

4.Missing parameters on called subprogram 5.Read/Write to unopened file 6.Move data from/to unopened file

S0C5-May be due to 1.Bad Subscript/index 2.Closing an unopened dataset 3.Bad exit from a perform 4.Access to I/O

area(FD) before read

S0C7-may be due to 1.Numeric operation on non-numeric data 2.Un-initialize working-storage 3.Coding past the

maximum allowed sub script

S0CB-may be due to 1.Division by Zero

Q52) What are the kinds of job control statements?

A52) The JOB, EXEC and DD statement.

Q53) What is the meaning of keyword in JCL? What is its opposite?

A53) 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) meanings are based on first, second and third position.

Q54) Describe the JOB statement, its meaning, syntax and significant keywords?

A54) The JOB statement is the first in a JCL stream. Its format is // jobname, keyword JOB, accounting information in brackets and keywords, MSGCLASS, MSGLEVEL, NOTIFIY, CLASS, etc.

Q55) Describe the EXEC statement, its meaning, syntax and keywords?

A55) 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.

Q56) Describe the DD statement, its meaning, syntax and keywords?

A56) The DD statement links the external dataset 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=dataset name. Other keywords after DSN are DISP, DCB, SPACE, etc.

Q57) What is a PROC? What is the difference between an instream and a catalogued PROC?

A57) 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 dataset.

Q58) What is the difference between a symbolic and an override in executing a PROC?

A58) 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.

Q59) What is RESTART? How is it invoked?

A59) RESTART is a JOB statement keyword. It is used to restart the job at a specified step rather than at the beginning.

Q60) What is a GDG? How is it referenced? How is it defined? What is a MODELDSCB?

A60) GDG stands for generation data group. It is a dataset with versions that can be referenced absolutely or relatively. It is defined by an IDCAMS define generation datagroup execution.

Q61) Explain concatenating datasets?

A61) Datasets 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 datasets.

Q62) What is the difference between specifying DISP=OLD and DISP=SHR for a dataset?

A62) DISP=OLD denotes exclusive control of the dataset; DISP=SHR means there is no exclusivity.

Q63) What is MOD and when would you use it?

A63) DISP=MOD is used when the dataset can be extended, ie, you can add records at the end of an existing dataset.

Q64) 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?

A64) 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.

Q65) How do you designate a comment in JCL?

A65) The comment statement is //* followed by the comments.

Q66) What is the meaning of the EXEC statement keyword, COND? What is its syntax?

A66) 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 - memorize it and don't ask questions!)

Q67) What is the improvement to COND= in the latest version of MVS?

A67) 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.

Q68) What is the purpose of the PARM keyword in the EXEC statement?

A68) The value after the PARM= specifies control information to be passed to the executing program of the job step.

Q69) What is the purpose and meaning of the REGION keyword and what JCL statement is it associated with?

A69) 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.

Q70) What is the purpose and meaning of the TIME keyword and what JCL statement is it associated with?

A70) 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.

Q71) What is the meaning of data definition name (ddname) and dataset name (dsname) in the DD statement?

A71) 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. Dataset name is the operating system (MVS) name for the file.

Q72) How is the keyword DUMMY used in JCL?

A72) For an output file DUMMY specifies that the output is to be discarded. For input it specifies that the file is empty.

Q73) What does the keyword DCB mean and what are some of the keywords associated with it?

A73) DCB stands for data control block; it is a keyword for the DD statement used to describe datasets. Keywords associated with it are BLKSIZE, DEN, LRECL and RECFM.

Q74) What is the difference between BLKSIZE and LRECL?

A74) LRECL is the logical record length , where as BLKSIZE is multiples of LRECL

Q75) Can you execute a PROC from another PROC?

A75) I did not know the answer and my interviewer said NO. Later I tried and executed PROC from a PROC, three levels deep. Manuals do not state any limit on PROC calling PROC, or nesting.

Q76) What will happen if you attempt to restart a job in the middle of a JCL // IF .... // ENDIF?

A76) Job will fall through to the ENDIF (not executing any steps), then resume execution with the first step AFTER the // ENDIF.

Q77) How many positional parameters are there in job statement?

A77) There are two position parameters in job statement.

Q78) What are three parameters you can specify on Job statement as well as on exec stmt ?

A78) Time, Region and Cond parameters

Q79) How can you trap abends in the JCL?

A79) Use IF ABEND statement in the JCL.

Q80) How do you restart a step in JCL?

A80) Use RESTART=step name.

Q81) How do you pass parameters to the program as the job is being executed ?

A81) By using 'parm' parameter in exec statement. the value mentioned here should be declared in linkage section in the program and process thru procedure division. this technique is very useful when you do not know the parameters at the time of coding the programs.

Q82) Why do you use a control card?

A82) A control card can be a member of a pds or a sequential dataset and is used for storing the date fields, Definitions of VSAM files....etc. You use control card because you cannot use a instream procedure in a procedure. Generally you will be calling a Proc from your Jcl and you cannot code instream procedure in the Proc and so you will point to the dataset which is called control card.

Q83) How do you submit JCL via a Cobol program?

A83) In your JCL define as //JOBA JOB 1111, JOB1 //STEP01 EXEC PGM=PROG1 //ddname DD SYSOUT=(*,INTRDR)....and your COBOL(PROG1) should look like this SELECT JCL-FILE ASSIGN TO ddname. Open this file and write the JCL statements into this file. E.g. MOVE '//TESTJOB JOB 1111,VISVEISH' TO JCL-REC.MOVE '//STEP01 EXEC PGM=IEFBR14' TO JCL- REC and close this file. Then TESTJOB will be submitted.

Q84) How do you submit a JCL under CICS environment ?

A84) Pass all the jcl codes to a COBOL variable(should be declare using OCCURS clause) and the write the line one by one to the spool using CICS commands like SPOOLClose SPOOLOpen SPOOLWrite . For more help reffer CECI of CICS or CICS manual

Q85) What is the parameter to be passed in the job card for the unlimited time , irrespective of the job class ?

A85) TIME=1440

Q86) Definition of COND parameter in JCL

A86) COND is a condition parameter, consists of 2 sub parameters, 1st - return code from the previous step, 2nd - condition. If COND is true, the step on which COND is coded will be BYPASSED.

Q87) What is meant by S0C7 system abend code?

A87) S0C7 - Data exception error - you will get it whenever you are trying to move the low values or spaces into the numeric field, or compare the numeric fields with low values, or try to do some arithmetic operations on the low values. To avoid this you have to always initialize the numeric fields otherwise they will contain the low values.

Q88) How to pass the temp dataset form one JOB step to another?

A88) By specifying the DISP as PASS for the temp dataset

Q89) What is a COND parameter in JCL?

A89) COND means condition parameter. It is compared with system return code of previous step.//step1 exec pgm=abcd//step2 exec pgm=xyz, cond=(4,lt)step2 will be executed when system return code of step1 is less than 4.

Q90) Write a jcl to execute a job by 7 a.m on Jan 20,1986 ?

A90) THE code IS : //*MAIN DEADLINE=(0700,B,012086)

Q91) How many types of libraries are there in JCL ?

A91) Libraries are of three types.1.Sytem Libraries: SUCH AS SYS1.LINKLIB2.Private Libraries: SPECIFIED IN A JOBLIB OR STEPLIB DD STATEMENTS.3.Temporary Libraries: CREATED IN A PREVIOUS STEP OF THE JOB.

Q92) What u mean by include statement in JCL ?

A92) An include statement identifies a member of a pds or pdse that contains. This set of JCL statements is called an include group. The system replaces the include statement with the statements in the include group.

Q93) The maximum number of in-stream procedure you can code in any JCL is ?

A93) Fifteen(15).

Q94) What you mean by skeleton JCl?

A94) Jcl which changes during run time i.e. the values for the jcl such as pgm name , dd name will change .ie same jcl can be used for various job, equivalent to dynamic sql...

Q95) How do you submit a JCL under CICS environment ?

A95) Edit the JCL in Extra partition TDQ and submit the same using some system command (not sure) under CICS subsystem. This is what i think, please clarify....

Q96) What is JCL ?

A96) JCL is Job Control Language and is used for Batch processing. The startup procedures of OS and standard products like CICS etc are written in JCL. It is interface between operating system(MVS) & application program. when 2 related programs are combined together on control statements is called job control language

Q97) What is the max blocksize for a Tape file?

A97) It is 32,760.Based on that we can calculate efficient number of Records in a Block

Q98) What are the basic JCL Statements for a Job?

A98) JOB : Identifies a job and supplies accounting info

EXEC : Identifies a job step by indicating the name of the program to be executed.

DD : Identifies a data set to be allocated for the job step

Delimiter(/*) : Marks the end of an in-stream dataset

Null(//) : Marks the end of a job

Comments(//*) : Provides Comments

PROC : Marks the beginning of a procedure

PEND : Marks the end of a procedure

OUTPUT : Supplies options for SYSOUT processing.

Q99) What does the statements: typrun=scan and typrun=hold do in a JCL statement

A99) typrun=scan checks the JCL for errors, typrun=hold holds the job until further notice.

Q100) Which is the most widely used batch performance monitor for DB2?

A100) DB2PM

Q101) What is QSAM error usually when it is occurs?

A101) Usually it is occurs at the time of job submission.

Q102) What is the purpose of include statement in a JCL?

A102) It is used as an alternative for STEPLIB. When we specify the dataset name in include ,it will search in all the datasets specified in the include dataset.

Q103) What does S0C4 error mean?

A103) This error is faced when we execute the COBOL program. The main reason for this error is that a variable is defined with less characters and we are trying to move data which is larger than the actual storage space.

Q104) In which table PLAN is registered in ?

A104) RCT

Q105) What is GDG?

A105) GDG - group of dataset that are logically or chronologically related, referred by name and a relative generation number - an integer which identifies the generation of a dataset and is coded in parentheses after dataset name. Absolute GDG name - GxxxxVyy, where xxxx-absolute gen. number, yy-version number. Can be sequential, direct, partitioned. (VSAM - no). Must always be cataloged. Advantage - all datasets have the same name and system keeps track of adding new and retaining previous generations and deleting oldest successive generation. To create a GDG we create a GDG index in the system catalog with IDCAMS utility and then a model (prototype, DSCB) on the same volume to supply DCB information. Empty - when limit is reached all members are removed from the index, otherwise-only oldest. Scratch-removed members are uncataloged & deleted, otherwise - removed & uncataloged, but remain in the system (not members of GDG any more). GDG number is updated at the end of the job. If number is not specified all generations will be processed from the beginning

Q106) what do you mean By spooling? Expand SPOOL?

A106) This is managed by JES. This is used for Queuing the Outputs that are intended for Printing and are first stored in SPOOLDASD. This can be managed Using

Q107) For how long a job can be executed continuously in a mainframe ?

A107) 248 DAYS

Q108) Max. No of DD statements in a job ?

A108) 3273

Q109) How much space OS allocates when you create a PS or PDS?

A109) 56 KB

Q110) Min no of member’s (PDS) in one directory block?

A110) SIX(6)

Q111) The maximum number of steps in a job?

A111) 255

Q112) How much is memory space involved, when we code BLOCKSIZE,TRK & CYL ?

A112) One block constitutes 32KB of formatted memory/ 42KB of Unformatted memory,6 blocks makes one Track & 15 Tracks makes one cylinder.

Q113) What is DSNDB06 ?

A113) This is the Place where DB2 Catalog resides

Q114) What is the use of DSNDB07 ?

A114) This is the area where sorting takes place in DB2

Q115) What is DATACOM db?

A115) It is a database used with VSE.

Q116) What is a Dummy Utility and what it does ?

A116) IEFBR14 is a Dummy utility and it is used for the sake of EXEC PGM= .... statement in JCL[when used it wouldn't perform any task]. e.g. While Allocating a dataset you don't have to run any utility [this could be done by giving disp=new inDD statement]. But for a PGM name must be given in EXEC statement, it is used.

Q117) What 3 guidelines do we have to follow when concatenating DD statements?

A117) Datasets must be of the same type (disk or tape), All datasets must have the same logical record length, The dataset with the largest blocksize must be listed first.

Q118) On the DD statement, what is the main difference between creating a new sequential flat file and a partitioned dataset?

A118) SPACE=(n,m) for a sequential file, SPACE=(n,m,p) for a PDS where n, m, and p are numbers. The p designates how many directory blocks to allocate.

Q119) What is the difference between IEBGENER, IEBCOPY and REPRO in IDCAMS utility?

A119) IEBGENER -- This is a dataset utility for copying sequential datasets which produces a PDS or a member from a

sequential dataset.

IEBCOPY -- This is a dataset utility for copying one PDS to another or to merge PDSs.

REPRO -- This is for copying sequential datasets. More or less same as the IEBGENER.

Q120) How do you submit JCL via a Cobol program?

A120) Use a file //dd1 DD sysout=(*,intrdr)write your JCL to this file. Pl some one try this out.

Q121) How to execute a set of JCL statements from a COBOL program ?

A121) Using EXEC CICS SPOOL WRITE(var-name) END-EXEC command. var-name is a COBOL host structure containing JCL statements.

Q122) What is the difference between static call & Dynamic call ?

A122) In the case of Static call, the called program is a stand along program, it is an executable program . During run time we can call it in our called program. As about Dynamic call, the called program is not an executable program it can executed thru the called program

Q123) What is the difference between catalogue procedure and In-Stream procedure?

A123) In Stream procedures are set of JCL statements written between JOB and EXEC statements, start with PROC and end with PEND statement. Mainly used to test cataloged procedures. Cataloged procedure is cataloged on the procedure library and is called by specifying the procedure name on the EXEC statement.

Q124) What do you feel makes a good program?

A124) A program that follows a top down approach. It is also one that other programmers or users can follow logically and is easy to read and understand.

Q125) Can we browse or edit the GDG dataset if it is a tape entry?

A125) No, You can’t edit or browse the GDG if it resides on tape.

Q126) What are the maximum and minimum sizes of any CONTROL AREA (VSAM datasets) ?

A126) Minimum Size : 1 track Maximum size : 1 cylinder

Q127) How to get cursor position from system in CICS environment ?

A127) Get it from EIBCURPOS !

Q128) How many parameters are there to a DISP statement and what are their uses ?

A128) There are three(3) parameters. Parameter 1: current data set disposition(new, shr, old, mod) Parameter 2: normal close action for data set (catlg, keep, delete) Parameter 3:abend action for data set (catlg, keep, delete).

Q129) What is the error code SOC01 indicate ?

A129) Operation exception error For e.g. a dataset open error

Q130) What is a procedure?

A130) A set of precoded JCL that can be modified through the use of parameters or override cards. Note: Procedures can be catalogued or instream.

Q131) What is the difference between specifying DISP=OLD and DISP=SHR for a dataset?

A131) OLD specifies exclusive use of a dataset, SHR allows multiple jobs to concurrently access the dataset Note: When updating a dataset, you would normally use OLD.

Q132) What are the three basic types of statements in a jobstream?

A132) JOB(one per jobstream)EXEC(one or more per job)DD(one or more per jobstep)

Q133) What does SYSIN * indicate?

A133) Instream data follows this card and is terminated when followed by a card containing // or /* in columns 1 and 2.

Q134) What are three major types of JCL statements? What are their functions?

A134) JOB - indicates start of jobstream to the operating system and through parms coded on it, certain details about the

job (time, region, message level, job accounting data).

EXEC - indicates the start of execution of a particular job step, be that step a program or a proc.

DD - is a data definition, which is used to describe the attributes of a data set (name, unit, type, space,

disposition).

1. Distinguish between positional & keyword parameters

2. How can you omit positional parameters ?

3. How do u define the identifier field for a delimiter statement ?

4. List some valid operation codes .

5. What is the purpose of the MSGLEVEL parameter ?

6. What is the function of the following parameters :

I) MSGLEVEL=(0,0)

ii) MSGLEVEL=(2,1)

iii) MSGLEVEL=(1,1)

7. What is the purpose of the MSGCLASS parameter ?

8. What are the parameters used with COND ?

9. List down the different types of comparison operators & their meaning .

10.What is the function of the TYPRUN parameter ?

11.What are the subparameters that can be used with TYPRUN?

12.What is the function of the TIME parameter?

13. What is the purpose of the EXEC statement ?

14. What are the additional keyword parameters used on the EXEC statement?

15. What is the difference between the following statements :

I) step#1 exec PGM=accpay

ii) step#1 exec tbalance

16. What is the error in the following JCL statements :

I) //step#three exec pgm=hkbc762

ii) //step#3 exec pgm = hkbc762

iii) //step#3 exec pgr = hkbc672

17. Name the system library from which modules are retrieved at execution time .

18. What is the purpose of the JOBLIB statement ?

19. If JOBLIB & STEPLIB statements are both included in a job , then which statement would overide .

20. What is the purpose of the PARM parameter ?

21. What is the pupose of the DD statement ?

22. How would u specify the device for a dataset in a DD statement ?

23. What is the function of the following DD statement //ddname DD *

24. What is the purpose of the SYSOUT Parameter in the DD statement ?

25. What are the two ways of specifying Temporary Data Sets ?

26. What are the advantages of coding the DISP parameter with MOD rather than NEW ?

27. Explain the function of the following Statement : //ddname DD DISP=(NEW,CATLG,DELETE)

28. What is the default value of the third DISP subparameter ?

29. What is Backward Referencing ?

30. What is the purpose of Concatenating Data Sets ?

31. What is the result of a READ operation on a Dummy Data set ?

32. What are the functions of the following ddnames : SYSUDUMP , SYSABEND , SYSMDUMP

33. What are GDGs ?


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