Introduction to DBMS Interview Questions and Answers
The 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.
If you are looking for a job related to DBMS, you need to prepare for the 2021 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 2021 DBMS Interview Questions article, we shall present the 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 Interview Questions and Answers.
Q1. DBMS is one of the popular management systems for various 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 around varieties of data available in the industry. This is one of the key systems that help users store multiple kinds of data systematically, define the characteristics of data,and retrieve smoothly whenever required to 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 the exact meaning of a database?
The database can be defined in a variety of approach. In a simple way, we can say the database mainly handles the collection of multiple types of data, storing the same in a define organize way,giving key facility for the user for retrieving the same smoothly. It can also manage proper accessing of a specific user on the data and ensure uploading critical data properly.
Let us move to the next DBMS Interview Questions.
Q3. There have a lot of uses available in terms of DBMS utilization. Explain what can be recommended to use in DBMS or specifically explain major advantages available in case of using DBMS properly?
Some of the critical advantages of using DBMS is explaining below:
- Redundancy management: DBMSmainly uses to support one of the key mechanisms for controlling redundancy of data inside one of the databases 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 the case of DBMS to share entire data with multiple users who belong to the different role, which defines be the database administrator.Moreover, it is possible to share the same database with multiple users.
- The 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 the 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 minimizing 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 a data definition language. This is used to properly define the database and schema, maintaining some schema structure properly by creating, truncating, altering, renaming, and dropping.
- DCL: DCL is standing for data control language. It is used to control multiple users’ access inside one of the databases 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 Interview Questions and Answers.
Q6. SQL is one of the major functionality for performing any kind of execution with data, specifically in DBMS. Explain 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 relational databases in some form of inserting, deleting or updating data from the defined database.
Q7. Explain in detail the common concept of Primary key and Foreign Key in DBMS for any database?
The 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.
Q8. Explain in detail the difference between Primary Key and Unique key for the DBMS environment?
Some of the key differences between the primary key and a unique key are defined below:
- One of the main differences between the primary key and the unique key i that the, primary key will never accept any kind of null value on that specific column of that table, and a unique key can accept the null value for that specific column.A single table 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 detail 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 a 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 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 –