JCL Interview Questions and Answers blog provides valuable information that will assist your preparations for success.

Here, we cover various JCL interview questions that may help prepare you.

JCLs control job execution, manage data storage needs, and perform various system tasks.

An interview may involve questions on JCL syntax, job sequencing parameters, and parameters for JCL scripts as part of an interview test.

As part of your preparation, this JCL mainframe interview questions blog will present common JCL interview questions with clear explanations, examples and strategies for answering them effectively and confidently.

Regardless of whether these JCL interview questions for experienced blogs provide the knowledge or skills to advance in mainframe careers or help secure your first job within it, whatever your aim may be.

Let’s investigate some JCL sort interview questions. Happy learning.

1. What is JCL?

JCL, or Job Control Language, is a programming language used in mainframe environments to communicate between the operating system and program resources.

It is essential for executing job steps and is used in various job processing stages.

2. What is a job in the context of JCL?

A job consists of many steps specified in job control language through a set of job control statements.

3. What is the role of JES in JCL processing?

JES, or Job Entry System, is responsible for receiving jobs, scheduling them for processing, and controlling output.

It decides the job’s PRTY based on class and PRTY, checks for JCL errors and determines whether and when to execute the job.

4. What are the different stages of job processing in JCL?

The different stages of job processing in JCL include submission and conversion.

When JCL is submitted to JES, the initiator selects a job for execution, attaches an interpreter, and converts it into interpreted text for JES to understand.

5. What are some of the parameters used in JCL statements?

JCL includes various statements, such as Adhesive, Job, Exec, and DD.

Each type has its own set of parameters, such as step names, position, keyword, time, and region parameters.

Understanding these parameters is crucial for effective programming and efficient JCL execution.

6. What is the role of JCL in mainframe environments?

JCL, or Job Control Language, is a programming language that communicates between the operating system and program resources in mainframe environments.

It is utilised throughout the task-processing lifecycle and is critical for executing job steps.

7. What is the purpose of the time parameter in JCL?

The time parameter specifies the CPU allocated for a particular step in JCL.

It allows you to give time for that step and your job, ensuring efficient resource use.

8. What is the function of the region parameter in JCL?

The region parameter specifies the amount of central storage occupied when specific steps in JCL are executed.

It helps manage resource use and prevent potential issues with insufficient storage.

9. What event triggers job execution in a system?

Job execution occurs when the job reaches the highest PRTY in the system.

10. What is the purpose of the DD statement in JCL?

The DD statement in JCL defines and controls data sets, specifying their names and other properties.

11. What is the DCB parameter used for in a DD statement?

The DCB (Data Control Block) parameter specifies the data set or file name in a DD statement.

12. How does the system determine whether a file is a PS or a PDS file?

Based on the JCL-specified file type, the system determines whether a file is a PS file (sequential) or a PDS file (direct).

13. What two modes can you create data sets, and how can you use utility mode?

Data sets can be created in two modes: utility mode and JCL mode.

Connect to the main terminal and select the ISPF primary option minnow to start a utility mode data set.

You can find various options like settings, views, edit, utilities, foreground, branch, command, and more.

14. What is the first step in creating a data set in utility mode?

The first step in creating a data set in utility mode is to select option two, which allows hyper-removing, copying data, at least searching, and selecting two possibilities.

15. In what mode can you view the data set after creation?

The data set can be viewed in various modes: view, edit, browse, or JCL.

16. How can you create a JCL job card for creating a data set?

Entering the JCL library and ID 14 for the IBM utility will obtain a JCL job card for creating a data set.

17. What is the purpose of cataloguing in JCL?

Catalogue frogs in JCL define common resources that multiple jobs can access.

They are defined outside JCL programs in a PDF member with the OPERAND statements.

18. What is the role of a catalogue procedure in JavaScript, and where should it be coded?

A catalogue proctor is a crucial component in JavaScript that must be coded within a JCL program immediately after job point number one.

It is available only for the declared job and cannot be used in other jobs.

19. What represents a data set name in a DD statement?

A data set name is represented by a file name following the DD statement, such as test.ps1 or PDS.

20. How are symbolic parameters used to define catalogue procedures, and what is an example of updating an input file name?

Symbolic parameters, user-defined prefixes with a single program, define the procedure.

For example, to update the input file name in an existing proc, the first step should be the job card and the proc name, and the second step should be the step name to use the test data or the raw data.

21. What is the difference between PS files and PDS files?

PS files are individual files that cannot be further divided, while PDS files create one data set within the data set.

PS files are single files, while PDS files are folders containing multiple files.

22. What are the differences between end-stream and catalogue procedures?

End-stream procedures are defined within a JCL program, while catalogue procedures are defined outside a JCL program.

No proclitic is required to locate the proc in catalogue procedures, and a bend statement is necessary to terminate the proc.

Additionally, 15 procedures can be defined in end-stream procedures, while unlimited procedures can be defined in catalogue procedures.

23. What are the advantages of using a catalogue in JCL?

The advantages of using catalogue frogs in JCL include reusability, as they can be stored in a common area and called multiple times when needed, and standardisation, which can be defined once and used across various applications.

24. What are BDS files, and what are the two types of data sets in this context?

BDS files are a data management system used in IBM’s iSeries or AS/400 platform.

The two types of data sets in BDS files are physical sequential files (PS) and partition data sets files (PDS).

25. How are global catalogue procedures created, and what is their availability?

Global catalogue procedures are created in a separate member with the proc operand and no pin strength.

They can be executed from any job across the application; only one process is coded from one job.

26. How is a PDS file created?

Creating a PDS file involves creating a folder within the library, multiple files, or a file without creating a folder.

The process begins with creating a test. A PDS file uses the same disposition and organisation parameters as a PO for PS.

The data set organisation is PO for PDS files, and the primary and secondary quantities are used for a partition.

27. How are different partitions created within a PDS file?

The partition number is given to create different partitions within a PDS file, and the GCL is submitted.

The maximum condition code is 0, and the data set name type is PDS. The creation day is followed by creating a member in the PDS file.

28. What is the advantage of using PDS files?

The main advantage of using PDS files is that they allow for creating multiple files within a folder, unlike PES files, which are single files.

29. What are the two types of files in the JCL and their characteristics?

The creating PS or flat files, which are two types of files.

Fixer block files have fixed record lengths, while variable block files vary by record.

The first step is to create a fixer block file, followed by a variable block file.

30. What are the three essential statements when writing a case in SAS?

JOB, EXEC, and DD statements.

31.What information does the job statement contain?

All job-related information marks the beginning of a job and also specifies the name of the job.

32. What is the purpose of the position parameter in a DD statement?

The position parameter in a DD statement tells the system to create a new file for the provided data set name or to delete an existing one if the creation fails.

33. How is a fixer block file created using the DD statement?

With a file name, disposition parameter, new catalogue deletes, data set organisation, and unit dimension.

The record length should be 80 or 23 bytes, and the block size should be 0.

34. What is the importance of catalogue procedures in real-time applications?

Catalogue procedures are essential in real-time applications as they allow for various operations and changes in data set names.

For example, if a common proc is defined for all regions, the data set names will change based on the requirement.

35. What diagnostic messages are provided by SYSPRINT and SYSOUT systems?

They provide diagnostic messages related to specific data sets and log messages related to the program.

36. How is a job submitted in SAS?

Type “SUV” at the command prompt and enter the job ID.

37. What information does the message log provide in SAS?

It provides information about the start and end of a job, memory allocation, and step execution.

38. What is a BS file’s default format and record length in SAS?

It is a BS file with a fixed block format and a record length of 80 bytes.

39. How is a BS file edited in SAS?

By typing “E” and entering data. The maximum number of lines and length is 80 bytes.

The columns show the length and direct code of the records. The fixer block is used to capture data.

40. What information does the message log provide about a data set in BSL files?

The message log provides information about creating and managing a data set, its properties and organisation.

41. How is a variable block created in a BSL file using JCL and three statement jobs: exec, steady, and test?

The text describes a process for creating a variable block in a BSL file using JCL and three statement jobs: exec, steady, and test.

The data set organisation remains the same, with the PS file and record format being VB.

The maximum record length is 80 bytes, and the block size is 0. The data set is successfully created when the log is checked.

42. How can you view the properties of a copied data set in BSL files?

To view the properties of a copied data set, type the “enter” and “S” commands in BSL files.

43. What is the record format of a variable block in BSL files?

The record format of a variable block in BSL files has been changed from fixed block to variable block.

44. What is the recall of a variable block in BSL files?

The recall of a variable block in BSL files is 80 bytes.

45. What is the primary usage of a variable block in BSL files?

A variable block is most commonly used in BSL files when programming requires a record length in a varying format.

It is used for data sets or EPS files and is particularly useful when there are records with varying formats, such as 10 bytes, 20 bytes, 30 bytes, or 10 bytes.

46. How can understanding the differences between fixed and variable blocks be practised in BSL files?

Creating different variables and fixed block lengths in BSL files can help understand their differences. This usage can be seen in Cobalt videos, where users learn how to write a program using a fixed block or available block, read data, and create variables or designated blocks.

47. How to delete a PS file in SAS?

To delete a PS file, check the disposition parameter to see if it is new or existing. If it exists, modify the dataset to delete the PS or any FB or variable block file.

To remove the dataset from the catalogue, type followed by the dataset name. The dataset has been successfully deleted if the maximum condition code is zero.

48. What are the different types of statements in JCL?

The Adhesive, Job, Exec, and D statements in JCL.

49. What technique should be used to delete a data site in the background?

In the background, users must write a JCL to delete or create a data site or PS file.

50.What is a position parameter in JCL?

A position parameter, such as PGM, is used in a program, like a load module or utility, and has a specific position in the JCL.

51. What default utilities does IBM provide for creating data sets, PDS, or sorting?

IBM provides default utilities for creating data sets, PDS, or sorting, which can be accessed using JCL’s IBM statement.

52. What are predefined or reusable steps used for in JCL?

Predefined or reusable steps, called Proc, can be used for various jobs in JCL.

53. What is a keyword parameter or con parameter in JCL?

A keyword parameter or con parameter is a parameter that has written code and an operator, specifying whether the previous step is less than or not and can be executed if it is less than.

54. What determines the record format in a data set?

The record format in a data set can be a desert vector block, variable block, or fixed block, depending on the specific requirements.

55. What is the role of the space parameter in the mainframe for data sets?

The space parameter in the mainframe specifies the amount of space allocated for data sets, which can be measured in MBs or kilobytes.

This helps save time and can be indicated by the primary and secondary parameters, with the primary being used first and the secondary being used after the primary space is filled.

Once the space is used, it is released for other usage.

56. What determines the record length in a data set?

Depending on the specifications provided in the JCL, the record length in a data set can be 80 bytes or a fixed byte.

57. What is an Include statement (DD statement) format in the mainframe?

The format of an Include statement (DD statement) in the mainframe is as follows: DD <ddname>, <DCB-space>, <unit>, <dataset-name>, <disposition-parameters>.

The first parameter is the rename, followed by the DCB space, unit, and dataset name. The disposition parameters specify whether to create a new or old data set.

58. What is the purpose of the unit parameter in the mainframe?

The unit parameter in the mainframe specifies the storage location for the data set and includes the volume or serial number.

59. What job card is in JCL, and how is it created?

A job card in JCL (Job Control Language) is a set of instructions that tells the mainframe how to process a batch job.

First, create a BDS (Data Set) with your ID and JCL lib to create a job card. The properties of the DD S should be set to B-O or BDS.

Then, use the DD statement to include the JCL instructions in the BDS.

60. What is the format for starting a job card in JCL?

To start a job card, use two forward slashes (null characters) followed by a job name, typically eight bytes.

61. What are the three parts of a job card in JCL?

The job card is divided into three parts: positional parameters, which provide account information for calculating bills, and keyword parameters, which are keywords for defining the job.

62. What is the role of Class A in a job card?

Class A is the first parameter in a job card, defining a specific group or area where the job is submitted.

It ranges from A to C and 0 to 9, and different classes are categorised based on the type of job.

63. What is MSGCLASS in a job card?

MSGCLASS are related to the message and categorised from A to Z or 0. For example, class A might be running a daily job or running from a specific time.

Class B is related to a print job, while class C is associated with a transmission from one system to another.

64. What is the purpose of a job card in JCL?

A job card in JCL is crucial for managing and executing job-related tasks.

65. What statements are included in a job card?

A job card contains three statements: an Execand a DD statement.

When submitting a batch JCL, it must print several diagnostic messages related to the job and specific statements at the DD level.

66. What are the most common columns in a job card, and what do they represent?

The most common columns in a job card are the team column and the COND keyword parameter.

The team column is used to start a team, while the COND keyword parameter is used to identify the user who is submitting the job.

67. What is the role of the notify keyword parameter in a job card?

The notify keyword parameter in a job card shows diagnostic messages when a job is submitted.

68. What is the range of values for the PRTY parameter in a job card?

The PRTY parameter in a job card ranges from 0 to 15, with 10 being the default PRTY.

69. What are the parameters used in a job card?

The parameters used in a job card include an identifier (Null character), job name, positional parameters, keyword parameters, job accounting information, programmer name, class message, message level, notification, and pre-order.

70. How do you create a job card in JCL?

To create a job card in JCL, first create a BDS with your ID and tell ST JCL lib.

The properties of the BDS should be like BO or BDS. The job card is divided into job name, positional parameters, and keyword parameters.

It starts with two forward slashes (null characters) and is occupied by two bytes.

It contains account information used to calculate bills and generate bills, as well as accounting information or programmer name, which can be provided as a PS file.

71. What is the first parameter in the DDS statement of a JCL, and what information does it specify?

The first parameter in the DDS statement of a JCL is the file name.

It specifies parameters such as new catalogue delete, data set organisation record, space, tracks, primary secondary release unit, volume serial number, and more.

72. What is the first statement in JCL, and what information does it provide?

JCL’s first and last statements describe the job, including accounting information, program name, class, PRTY, etc.

73. What is the purpose of the Exec statement in JCL?

The Exec statement in JCL represents different programming languages used in a mainframe.

It is followed by an Exec operand, positional parameters, keyword parameters, and a DD name to execute the program.

74. What is the role of the DD statement in JCL?

The DD statement in JCL determines the data set or files for a particular program within the JCL or job name.

It is one of the three crucial statements for understanding the programming languages used in a mainframe and their implications for program execution.

75. What different data storage methods does the mainframe use?

The mainframe uses other data storage methods, such as tracks and cylinders, which vary in size depending on the version and model used.

JCL (Job Control Language) is an integral component. Understanding it is necessary for managing and automating various job batches.

JCL defines tasks, data sets to be utilised, resources required, and the sequence of events needed to complete them successfully.

Candidates should anticipate questions related to JCL syntax, statements, libraries, directives, and troubleshooting when interviewing for a JCL position.

Preparing for an interview may involve reviewing JCL scenario-based interview questions, JCL documentation, PDFs, practising writing and interpreting statements, gaining production environment experience working with JCL statements, familiarising oneself with related commands, data sets, or concepts and becoming proficient in answering interview questions efficiently.

By focusing on these critical areas, candidates will be better equipped to face JCL tricky interview questions and demonstrate their knowledge and expertise in system administration.