Introduction to DBMS Interview Questions and Answers
Database management system (DBMS) is one of the key software in the IT industry for managing or creating any databases in the system. DBMS mainly provides a big utility to the programmer or specific user for creating, updating, deleting or storing data by using some systematic way.
Now, if you are looking for a job which is related to DBMS then you need to prepare for the 2020 DBMS Interview Questions. It is true that every interview is different as per the different job profiles. Here, we have prepared the important DBMS Interview Questions and Answers which will help you get success in your interview.
In this 2020 DBMS Interview Questions article, we shall present 10 most important and frequently asked DBMS interview questions. These interview questions are divided into two parts are as follows:
Part 1 – DBMS Interview Questions (Basic)
This first part covers basic DBMS Interview Questions and Answers.
Q1. DBMS is one of the popular management systems for varieties database, explain in details about where and how the database management system (DBMS) can be used?
DBMS is called a Database Management System. One of the key purposes of using the application system revolves with varieties of data available in the industry. This is one of the key systems which helps users for storing multiple kinds of data in a systematic way, define the characteristics of data, retrieve smoothly whenever require an update that specific data on that corresponding database properly.
Q2. We are normally telling we need the database for storing and handling data. What can be the definition or what is exact meaning of a database?
The database can be defined in varieties approach. In a simple way, we can say the database is mainly handling the collection of multiple types of data, storing the same in define organize way, give key facility for the user for retrieving the same smoothly. It also can able to manage proper accessing of a specific user on the data and ensuring uploading critical data in a proper manner.
Let us move to the next DBMS Interview Questions.
Q3. There have some lot of uses available in terms of DBMS utilization. Explain what can be the recommended to use in case of DBMS or specifically explain about major advantages available in case of using DBMS properly?
Some of the critical advantages of using DBMS is explaining below:
- Redundancy management: DBMS is mainly using for support one of the key mechanism for controlling redundancy of data inside one of the database by integrating the same into one specific single database. As data has been stored in one single database, so there has no chance of duplicity.
- Sharing of Data: It is possible in case of DBMS to share entire data with multiple users who belong to the different role which defines be the database administrator. It is possible to share the same database with multiple users.
- Facility of taken back up and recovery of data.
- Ensuring to maintain proper integrity constraint.
- Maintain full independence of multiple data.
Q4. DBMS one of the common characteristics of following normalization of data. What would be the purpose of using normalization especially in case of recommended by DBMS?
This is the common DBMS Interview Questions asked in an interview. Several responsibilities normally need to follow by a DBMS tester in the current IT industry. Normalization is one of the key properties specifically for the relational database management system (RDBMS). It is one of the important processes for analyzing multiple relational schemas where they have some dependency based on their different functional point of view and have to maintain one primary key for defining some of the key properties. Properties are defining below:
- Concentrating on minimizing data redundancy as much as possible.
- Ensuring on minimize deleting, updating or inserting data anomalies.
Q5. Explain in details about the available languages in the database management system (DBMS)?
There have several kinds of languages available in DBMS, please find below details:
- DDL: DDL is defined as data definition language. This is used to give some proper definition of the database and schema maintaining some schema structure properly by using create, truncate, alter, rename and drop.
- DCL: DCL is standing for data control language. It is used for controlling varieties access of multiple users inside one of the database by using some of the key SQL queries like REVOKE or GRANT.
- DML: DML stands for data manipulation language, it has been used for manipulating data available in one single database by using some key SQL queries INSERT or DELETE. Others set of SQL queries can also be considered as DML like SELECT, DELETE, INSERT or UPDATE.
Part 2 – DBMS Interview Questions (Advanced)
Let us now have a look at the advanced DBMS Interview Questions and Answers.
Q6. SQL is one of the major functionality for performing any kind of execution with data specifically in DBMS. Explain about the specific purpose of using SQL in DBMS?
SQL is basically called the structured query language. One of the main purposes of using the same is to interact with one of the specifically define the relational database in some form of inserting, deleting or updating data from the defined database.
Q7. Explain in details about the common concept of Primary key and Foreign Key in case of DBMS for any database?
Primary key and Foreign key is mainly using for any kind of relational database management system. The primary key is basically ensuring the integrity of one specific table entire data security, ensuring one unique identification of that specific record in that database table. Whereas foreign key is mainly maintaining one relation of one specific column of that table with one another table specific column where another table specific column will be the primary key of that table.
Let us move to the next DBMS Interview Questions.
Q8. Explain in details about the difference between Primary Key and Unique key for DBMS environment?
Some of the key differences between primary key and a unique key are defined below:
- One of the main difference between primary key and the unique key is, primary key will never accept any kind null value on that specific column of that table, and unique key can accepting the null value as well for that specific column.
- In a single table, it should have one single primary key, whereas a unique key can be multiple in a single table.
Q9. There have one of the big concepts of the subquery. Explain in details about the subquery specifically in terms of SQL query?
This is the most popular DBMS Interview Questions asked in an interview. Some popular test cases in the current IT industry. A subquery is one of the concepts of writing query inside some other query. It also has one popular name called inner query which actually belonging under some outer query.
Q10. Give some more details about the differences between DROP, DELETE and TRUNCATE commands clearly?
DROP, Delete and Truncate are some very frequently used SQL queries. Differences are:
DROP: drop the table including the entire structure in the database.
DELETE: delete some specific row of the table, not the structure of the database.
Truncate: truncating entire data available in the database, but not deleting the structure of the table.
This has been a guide to the list of DBMS Interview Questions and Answers so that the candidate can crackdown these DBMS Interview Questions easily. Here in this post, we have studied top DBMS Interview Questions which are often asked in interviews. You may also look at the following articles to learn more –