Comman DBMS Interview Questions

Are you looking to join an industry as a DBMS developer? Have you prepared yourself to face DBMS interview questions? If not, then dig into some technical insights for DBMS. Database management has become popular more than ever. A set of logically arranged data for a specific purpose is commonly known as Database. A collection of programs, which can be used to create and maintain a database is known as Database Management System or DBMS. It is basically a systematic way of executing a command with data.

If one is through with the basics, half the battle is won. The more the knowledge on the subject, the easier will it be to crack the DBMS interview questions. There is a vast list of questionnaire available on Google to help you gain confidence before facing the interview panel.

Read Best DBMS Interview Questions

1. What is DBMS?

DBMS (Database Management System) is a computer software application that allows users and other applications to view, monitor and analyze data. It is an application to handle data on various subjects.
 

2. Enlist various types of interactions created by DBMS?

There are various kinds of interactions supported by DBMS like-
  • Data definition
  • Update
  • Retrieval
  • Administration

3. What are different relationships existing in database?

A relationship in database is established when one table has a foreign key that references the primary key of another table. There are three relationships existing between database-
  • One-to-one– This simple relationship exists among two tables having same rows or columns.
  • One-to-many– Two tables connected by a foreign key and a primary key enjoys one-to-many relationship.
  • Many-to-many – It is a complex relationship in which many records in one table is connected to many records in another table.

4. What are different cursor types?

A database cursor enables traversal over the records in database. The different cursor types are-
  • Dynamic – it is highly subject to changes while scrolling the cursor in database.
  • Static – it doesn’t show any changes while scrolling. It also works on recording of snapshot.
  • Keyset – it enables the user to modify the data without displaying the new data.

5. List few restrictions that are imposed while creating views?

There are certain restrictions that are applied while creating views in database-
  • Only current database can have views. No other database is allowed to have views other than the current database.
  • You cannot make any changes in the computed values of any view.
  • You cannot apply full text index definitions.
  • Temporary views cannot be created and temporary tables cannot have views.
  • It is not associated with any default definitions.
  • There are integrity constants that define the working of commands such as insert and delete.
  • Triggers such as INSTEAD of is associated with views

6. What is join? Mention its types.

Join depicts the relationship between two or more tables. It combines row of different tables and enables you to select data with reference to data of some other table. There are several joins in database like CROSS JOINs, NATURAL JOINs, EQUI-JOIN, etc. Two most important joins are –

  • INNER JOIN – this join returns values that have matching record in both the tables. In this, blank rows are combined in middle.
  • OUTER JOIN– it returns all the records of left table. It also returns the values that match with the right table. Blank rows are put in specified side by joining tables in other side.

The above questionnaire for DBMS interviews comprises some basics and advanced level questions from the technical aspect. In the basic category, questions are asked regarding the definition and properties of a database, its advantages over the obsolete file processing system and disadvantages, E-R model, normalization, data definition language, data abstraction levels and so on. Being thorough with the subject can easily fetch you good remarks from the interviewer and will give you an edge over the others. Technical aspects also have advanced questions like interactions catered by the DBMS, extension and intension, system – R, etc., and even these are easy to answer. One may also check on integrity rules and different languages available in DBMS.