Interview Questions

Virtual Storage Access Method Topic to Prepare for Interview

VSAM is an IBM DASD file storage access method, first used in the OS/VS1, OS/VS2 Release 1 (SVS) and Release 2 (MVS) operating systems, later used throughout the Multiple Virtual Storage (MVS) architecture and now in z/OS. Originally a record-oriented filesystem.[NB 2], VSAM comprises four[NB 2] data set organizations: Key Sequenced Data Set (KSDS), Relative Record Data Set (RRDS), Entry Sequenced Data Set (ESDS) and Linear Data Set (LDS). The KSDS, RRDS and ESDS organizations contain records, while the LDS organization (added later to VSAM) simply contains a sequence of pages with no intrinsic record structure, for use as a memory-mapped file.

IBM uses the term data set in official documentation as a synonym of file, and Direct access storage device (DASD) because it supported other devices similar to disk drives interview questions.

VSAM records can be of fixed or variable length. They are organised in fixed-size blocks called Control Intervals (CIs), and then into larger divisions called Control Areas (CAs). Control Interval sizes are measured in bytes — for example 4 kilobytes — while Control Area sizes are measured in disk tracks or cylinders. Control Intervals are the units of transfer between disk and computer so a read request will read one complete Control Interval. Control Areas are the units of allocation so, when a VSAM data set is defined, an integral number of Control Areas will be allocated.

The Access Method Services utility program IDCAMS is commonly used to manipulate (“delete and define”) VSAM data sets.

Custom programs can access VSAM datasets through Data Definition (DD) statements in Job Control Language (JCL), via dynamic allocation or in online regions such as in Customer Information Control System (CICS).

Both IMS/DB and DB2 are implemented on top of VSAM and use its underlying data structures JavaScript.

The physical organization of VSAM data sets differs considerably from the organizations used by other access methods, as follows.

VSAM data sets consist of control intervals (CI) and control areas (CA). The size of the CI and CA is normally determined by the access method, and the way in which they are used is not visible to the user. There will be a fixed number of control intervals in each control area.

A control interval normally contains multiple records. The records are stored within the control interval starting from the low address upwards. Control information is stored at the other end of the control interval, starting from the high address and moving downwards. The space between the records and the control information is free space. The control information comprises two types of entry: a control interval descriptor field (CIDF) which is always present, and record descriptor fields (RDF) which are present when there are records within the control interval and describe the length of the associated record. Free space within a CI is always contiguous.

When records are inserted into a control interval, they are placed in the correct order relative to other records. This may require records to be moved out of the way inside the control interval. Conversely, when a record is deleted, later records are moved down so that the free space remains contiguous. If there is not enough free space in a control interval for a record to be inserted, the control interval is split. Roughly half the records are stored in the original control interval while the remaining records are moved into a new control interval. The new control interval is taken from a pool of free control intervals within the same control area as the original control interval. If there is no remaining free control interval within that control area, the control area itself is split and the control intervals are distributed equally between the old and the new control areas.

You can use three types of record-orientated file organization with VSAM (the contents of linear data sets have no record structure):

Sequential VSAM organization
Further information: Entry Sequenced Data Set
An ESDS may have an index defined to it to enable access via keys, by defining an Alternate Index. Records in ESDS are stored in order in which they are written by address access. Records are loaded irrespective of their contents and their byte addresses cannot be changed.

Indexed VSAM organization
Further information: Key Sequenced Data Set
A KSDS has two parts: the index component and the data component. These may be stored on separate disk volumes.

While a basic KSDS only has one key (the primary key), alternate indices may be defined to permit the use of additional fields as secondary keys. An Alternate Index (AIX) is itself a KSDS.

The data structure used by a KSDS is nowadays known as a B+ tree.

Relative VSAM organization
Further information: Relative Record Data Set
An RRDS may have an index defined to it to enable access via keys, by defining an Alternate Index.

Linear VSAM organization
Further information: Linear Data Set
An LDS is an unstructured VSAM dataset with a control interval size of a multiple of 4K. It is used by certain system services.

VSAM Data Access Techniques
There are four types of access techniques for VSAM data:

Local Shared Resources (LSR), is optimised for “random” or direct access. LSR access is easy to achieve from CICS.
Global Shared Resources (GSR)

Non-Shared Resources (NSR), which is optimised for sequential access. NSR access has historically been easier to use than LSR for batch programs.
Distributed File Management (DFM), an implementation of a Distributed Data Management Architecture server, enables programs on remote computers to create, manage, and access VSAM files.

Sharing VSAM data
Sharing of VSAM data between CICS regions can be done by VSAM Record-Level Sharing (RLS). This adds record caching and, more importantly, record locking. Logging and commit processing remain the responsibility of CICS which means that sharing of VSAM data outside a CICS environment is severely restricted.

Read more about VSAM Interview Questions and answers.

Sharing between CICS regions and batch jobs requires Transactional VSAM, DFSMStvs. This is an optional program that builds on VSAM RLS by adding logging and two-phase commit, using underlying z/OS system services. This permits generalised sharing of VSAM data.

Interview Questions

Angularjs Interview Questions And Answers For Freshers Pdf

Angularjs Interview Questions And Answers For Freshers Pdf

  • Explain AngularJS?
  • What is data binding in AngularJS?
  • Explain the scope in AngularJS?
  • What are the services in AngularJS?
  • Define the filters in AngularJS?
  • What is routing in AngularJS?
  • What is deep linking in AngularJS?
  • Which are the core directives of AngularJS?
  • Explain AngularJS expressions?
  • How to make an ajax call using Angular JS?
  • What is use of $routeProvider in AngularJS?
  • What is $rootScope?
  • What is a service?
  • What is provider?
  • What are the differences between service and factory methods?
  • What are the controllers in AngularJS?
  • What is AngularJS? Can you explain it technically?
  • Explain AngularJS boot process?
  • What are the key differences between AngularJS and jQuery?
  • Define jQLite?
  • Explain the disadvantages of AngularJS?
  • Explain what is directive and mention what the different types of Directive in AngularJS?
  • Is AngularJS a templating system?

AngularJS Interview Questions and Answers

Interview Questions

Ab Initio Scenario Based Interview Questions @

Read TOP Ab Initio Scenario Based Interview Questions pdf download, most asked Ab Initio Scenario Based Interview Questions for experienced freshers.


List of Ab Initio Scenario Based Interview Questions @

  1. Explain the difference between the truncate and delete commands?
  2. What does dependency analysis mean in Ab Initio?
  3. What is the difference between rollup and scan?
  4. How can i run the 2 GUI merge files?
  5. What methods exist for performance tuning? Ab Initio Scenario Based Questions
  6. What means writing of wrapper?
  7. What is the reason for using parameterized graphs?
  8. What is API mode versus the utility mode?
  9. What is the reason for a database to contain stored procedures?
  10. What is the purpose of ramp limit? Questions Scenario Based Ab Initio
  11. What is the role of a driving port?
  12. What can we say about partitioning with key and round robin?
  13. What is the definition of a multistage component?
  14. What are the supported layouts in Ab Initio?
  15. What can we say about the Scan component versus a RollUp component? Ab Initio Questions Scenario based
  16. What is the meaning of a DB config versus a CFG file?
  17. How the term Standard Environment can be explained?
  18. How much memory do we need for a graph?
  19. What difference does exist between Checkpoint and Phase? Ab-Initio Questions
  20. What role has the XFR function?
  21. What possible errors we can receive from a graph execution?
  22. What is the meaning of EME?
  23. What meaning has lock in Ab Initio?
  24. Can a graph be infinitely run? If yes, how?
  25. What is the component that can be used to lower a file in size?


Interview Questions

Toughest Interview Questions asked at Top MNCs


Some of the toughest interview questions which were asked at top MNCs different positions. These interview questions will help you answer well.

Position for Administrative Assistant at Google

If you were given a box of pencils, list 10 things you could do with them that are not their traditional use.

Question for Software Developer Postion at Microsoft

How would you test an elevator?

Senior Recruiting Manager at Amazon

How would you solve problems if you were from Mars?

Apple Software Engineering Manager

Tell me something that you have done in your life which you are particularly proud of.

Question asked for Sales Associate at Pacific Sunwear

If you were a street sign what would you be?

Technology Analyst at Goldman Sachs

There are infinite black and white dots on a plane. Prove that the distance between one black dot and one white dot is one unit.

Internet Marketing Analyst at Facebook

A Russian gangster kidnaps you. He puts two bullets in consecutive order in an empty six-round revolver, spins it, points it at your head and shoots. Click. You’re still alive. He then asks you, do you want me to spin it again and fire or pull the trigger again. For each option, what is the probability that you’ll be shot?

Question asked for the Financial Analyst Postion at JP Morgan Chase

Tell me a joke.

Product Manager at Google

How much would it cost to implement a product improvement for the entire US?

Recruiter at Twitter

Why wouldn’t I hire you?

Technical Support Position Questions asked at Valve Corporation

What are the best dates to run marketing campaigns in your country?

Product Tester at MTD Products

How do you feel about working in extreme weather conditions all year round?

Retail Sales Specialist at Sony

If you were to be a Sony product, what would you be?

Summer Intern at AIG

Describe a time when you encountered ambiguity and how you dealt with it.

Manager at Deloitte

Which three people that you don’t know do you admire the most and why?

Question for Engineering Technician at Tesla Motors

How would you describe a dynamometer to an 8-year-old child?

Product Manager at Google

How would you estimate how many radio stations are in the US?

Software Engineer at Electronic Arts

What was your biggest failing in your career?

Read these Toughest INTERVIEW QUESTIONS asked at Top MNCs & get success in job interview.