In the era of the 21st century, we as social beings can’t imagine leading our lives without data. This post from CrunchyTricks states that approximately 2.5 quintillion bytes of data are produced in the modern world. So, it is critical for all of us to review this data and produce the necessary results by using the database management systems(DBMS) (DBMS). Learning DBMS allows you to pursue a career as a database administrator.
A database is the foundation of every IT system. Having a profound knowledge and expertise in the database management system(DBMS) is very crucial.
In this article, I’ll go over the most popular DBMS interview questions and their responses. There are three types of questions: general, SQL-based, and query-based. These were gathered after speaking with people who are experts in this area.
1. What is the concept of a database?
Answer: A database is a list of structured data that is electronically stored. Such well-organized information is simple to view, aggregate, and maintain. A Database Management System is used to administer and track the database.
2.What is the aim of a DBMS (Database Management System)?
Answer: Database management systems (DBMS) are software tools that assist you in creating and maintaining logically linked files, also known as databases. Here are some of the uses of database management system:
- The redundancy of data is controlled.
- Unauthorized entry is prohibited.
- Integrity constraints are enforced.
- Data exchange and accessibility.
- Protection and preservation of data.
3.Describe the various categories of database management systems.
Answer: The below are the various categories of database management systems:
- Relational DBMS (RDBMS): This style of the database management system (DBMS) employs a mechanism that enables users to view data compared to other data in the database. Tables are used to store data in this form of DBMS.
- Hierarchical DBMS: As the name implies, hierarchical DBMSs have a tree-like structure, with nodes representing records and branches representing fields.
- Network DBMS: Many-to-many relationships are supported by this model of DBMS, which allows multiple participant records to be connected.
- Object-oriented DBMS: Small bits of software called objects to store data and instructions for what to do about it.
4.What are the benefits of a database management system (DBMS)?
Answer: The below are some of the benefits of using a database management system:
- Data sharing: Data from the same account can be used by several users at the same time.
- Integrity constraints: These limitations allow for more refined data storage in a database.
- Data redundancy control: Supports a mechanism for controlling data redundancy by combining all data into a single database.
- Data Independence: This allows the data structure to be changed without affecting the structure of any running application programs.
- Backup and recovery function: Provides a backup and recovery feature that automatically creates data backups and restores data if and when needed.
5. Mention the various DBMS languages available.
Answer: The following are the various languages used in DBMS:
- DDL (Data Definition Language) is a collection of commands used to describe a database.
- DML (Data Manipulation Language) is a collection of commands that You can use to manipulate data in a database.
- DCL (Data Control Language) – Consists of authorities that deal with database system user permissions and controls.
- TCL (Transaction Control Language) is a collection of authorities that deal with database transactions.
6.What exactly does DBMS data abstraction imply?
Answer: Data abstraction is the process of shielding redundant information from users so that communications with them are as seamless as possible. Abstraction is divided into three levels:
- Physical Dimension: This is the most fundamental level of abstraction, describing how data is mechanically processed in memory. Data can be obtained in two ways: sequentially or randomly. B+ trees and hashing techniques are used to arrange the files.
- Logical Dimension: Information is stored in the form of tables at this level. Simple constructs are often used to store relationships between different entities.
- View Dimension: The term “view level” refers to the highest level of abstraction.
7. What are the ACID properties of a database management system?
Answer: Atomicity, Consistency, Isolation, and Durability (ACID) are acronyms for Atomicity, Consistency, Isolation, and Durability, respectively. It is used to ensure that data transfers in a computer system are processed reliably.
- Atomicity: Atomicity refers to transactions that are either entirely efficient or completely unsuccessful. Each marketing here refers to a single logical data process. As a result, even if one element of a process fails, the transaction as a whole fails, leaving the database state unchanged.
- Consistency: It means that the data adheres to one of the validity guidelines. In basic terms, the transaction never goes the ledger until it has completed its state.
- Isolation: Concurrency management is the primary objective of isolation.
- Durability refers to the fact that if a contract is committed, it can take place regardless of the circumstances.
8.What is a checkpoint in a database management system, and when does it happen?
Answer: A checkpoint is a process that removes all previous logs from the device and stores them indefinitely on the data disc. Checkpoints are those points in the transaction log record from which You can recover all committed data up to the end of a crash. The lack of indexing in a traditional file-based system transmits us with the unique option of scanning the complete page, making the admittance of content tedious and super slow. The additional issue is redundancy and inequality as files have many parallel and redundant data, and turning one of them makes all of them inconsistent. Obtaining data is harder in traditional file-based systems because the information is unorganized in them.
So, here are a few basic DBMS questions for beginners who aspire to become database developers soon. All the very best! Shine bright like a star. We hope you’ve found our article worthy and it helped you gain confidence! Do well!