When the internet became globally available, the amount of data created every day exploded. Storage requirements went from gigabytes to exabytes, and then cloud databases emerged. But what is a database management system (DBMS)? In this blog, we will define DBMS, and learn about its concepts and features.
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What is a Database?
Before understanding what DBMS is, let us first understand what a database is. In layman’s terms, the database is a big container where data is stored in a structured format. We cannot store semi-structured or unstructured data in a database. A database is an organized collection of data that can be modified, retrieved, or updated.
Data, DBMS, and applications associated with them together form the database concept. The data, stored in the database, is in the row and column format, which is called a table. Every website, which needs us to sign up, uses a database. There is no internet without databases.
Check out the difference between Data Warehouse vs Database.
What is DBMS?
DBMS stands for the database management system. It is a software system designed for managing and organizing the data in a planned manner. It is used for storing, fetching data, and running queries on data.
A database management system is an intermediate software between the end-user and the database that allows the manipulation and storage of data.
Types of DBMS
1. Relational Database Management System (RDBMS)
Relational database management systems are used for organizing relations or tables consisting of rows and columns. In RDBMS, each row denotes a record, and each column represents a particular attribute of a record.
RDBMS makes use of structured query language (SQL) for managing and querying data in databases.
2. NoSQL Database Management System (DBMS)
NoSQL database management system stands for Not Only SQL. These database management systems are used for handling a vast amount of unstructured or semi-structured data.
NoSQL not only works with relational data formats but also with key-value pairs, document-oriented, column-oriented, and graphical databases.
3. Object-Oriented Database Management System (OODBMS)
Object-oriented database management systems store data as objects, similar to the object representation in OOPs, i.e., object oriented programming languages.
OODBMS is utilized in programs and applications with complex data structures and relationships.
4. Hierarchical and Network database management system
Hierarchical and network databases, as the name suggests, organize the data in a hierarchical or network-like structure, where records are linked as parent-child or network relations.
Hierarchical and network DBMS are utilized in specialized applications, such as Information Management System (IMS) or Integrated Database Management System (IDMS).
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Components of DBMS
- Data Model: It is used for defining the structure of a database and how data should be organized and related to each other. The relational model, hierarchical model, network model, and object-oriented model are some of the data models.
- Database Schema: It is a pattern that defines the logical structure of the database, including tables, fields, relationships, and indexes.
- Query Language (SQL): Structured query language is used for managing and querying relational databases. It allows users to create, insert, update, remove, and retrieve data.
- Storage Management: It includes tasks like data storage, indexing, and data compression. It is responsible for efficiently managing the allocation and management of storage space.
- Concurrency Control: It is responsible for ensuring that the users have access to and can modify the databases without interrupting transactions in the system. Using this, inconsistency and conflicts are easily avoided in database systems.
- Security Features: DBMS’s security includes authentication, authorization, encryption, and auditing mechanisms. These features protect the database from unauthorized access.
Also, read about the entity in DBMS.
Relational Database Concepts
- Tables and Rows: Tables are fundamental structures in a relational database, representing entities or concepts. Rows, also known as tuples or records, contain the actual data in the entries.
- Primary Keys and Foreign Keys: Primary keys uniquely recognize each record in a table, and the foreign key is used for establishing entities or concepts.
- Relationships: It defines how entities or tables are linked to each other, either one-to-one, one-to-many, or many-to-many.
- Normalization and Denormalization: Normalization is the process of organizing data in a database to reduce redundancy and increase data integrity. Denormalization is the process of adding redundancy to improve query performance.
Also, check out the blog on Data Independence in DBMS.
Applications of DBMS
DBMS is an essential tool used for retrieving, storing, and managing data. Some common applications of DBMS in various fields can be seen in these areas:
- Enterprise Resource Planning (ERP) Systems
- Customer Relationships Management (CRM) Systems
- Online Transaction Processing (OLTP) Systems
- Data Warehouse and Business Intelligence (BI) Systems
- Healthcare Information Systems
- Educations Systems
- Supply Chain Management Systems
- Social Media Platforms
Few examples can be seen below:
| Sector | Application |
| Universities | Student information, courses, grades, etc. |
| Sales | Customer information, sales, etc. |
| Finance | Stock information, sales, bonds, etc. |
| Banking | Customer information, account, activities, deposits, loans, etc. |
| Manufacturing | Production information, suppliers, inventories, etc. |
| Airlines | Customer information, schedules, reservations, etc. |
| HR Management | Employee information, payroll, deduction, paychecks, etc. |
| Telecommunication | Call records, bills, usage, etc. |
Also, learn about serializability in DBMS.
Advantages and Disadvantages of DBMS
| Advantages of DBMS | Disadvantages of DBMS |
| Various formats of data can be stored, and data can be retrieved by a range of methods in the Structured Query Language. | In some cases, DBMSs are highly complicated systems to set up and maintain. |
| As most databases are usually centralized in nature, they can be accessed quickly and managed easily. | The cost of DBMS hardware and applications is comparatively high, exhausting an organization’s budget. |
| We can set up authorized users who can view, share, and access data. This ensures security for data. | In certain organizations, all information is integrated into a common database, which may get destroyed due to electrical issues or it may get corrupted in storage media. Having backups is preferred in such situations but that increases the cost. |
| DBMS facilitates the smooth incorporation of programming languages, such as C++, Python, and PHP, to allow users to establish a connection with a web application or third-party applications. | Certain DBMS systems cannot run complex queries as they slow down the other processes that are running. |
SQL Basics
Let’s go through some of the basic concepts in SQL that will help you get a better perspective on how DBMS can be navigated with the help of SQL.
1. Data Definition Language (DDL): DDLs are used for defining the structure and schema of the database. Common DDL commands are CREATE, ALTER, and DROP.
2. Data Manipulation Language (DML): DML is used for manipulating and operating on data. INSERT, UPDATE, DELETE and SELECT are common queries.
3. Data Query Language (DQL): It is used for querying and retrieving the data. SELECT, along with conditions, is used to retrieve data.
4. Data Control Language (DCL): It controls access to data within the database. GRANT and REVOKE are the commands used in DCL.
5. Transaction Control Language (TCL): This manages transactions, ensuring the ACID properties (Atomicity, Consistency, Isolation, and Durability). BEGIN TRANSACTION, COMMIT, and ROLLBACK are a few common commands.
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DBMS Softwares
A few examples of DBMS are as follows:
- MySQL: MySQL is known for its scalability and fast performance. It is used in Facebook, Twitter, YouTube, Airbnb, and Pinterest the software is widely utilized for web applications.
- Oracle Database: It is a commercial relational database management system known for robust features and high performance and is used by Amazon, Walmart, and Banking companies such as Bank of America.
- Microsoft SQL Server: Microsoft SQL Server is known for its integration with other Microsoft products and services and is widely used by Stack, Overflow, Dell, Nasdaq, Siemens, and Volvo.
- PostgreSQL: It is a powerful open source object-relational database system. It is robust and reliable and is used by Apple, Spotify, Etsy, Reddit, and Instagram.
- SQLite: It is a lightweight, self-contained, serverless, and transactional SQL database engine and it is used in embedded systems, mobile applications, and small-scale database deployment. It is used in companies like Mozilla, Dropbox, Skype and Adobe.
- MongoDB: It is a popular open-source NoSQL database that is flexible and scalable and is good at handling unstructured and semi-structured data. It is utilized by Adobe, eBay, and Google.
- Cassandra: Apache Cassandra is a distributed NoSQL DBMS system used in Netflix, Apple, eBay, and Uber.
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Conclusion
Whether you’re a database administrator, developer, data analyst, or work in a DevOps role, mastering PostgreSQL can enhance your skill set and contribute to the improvement of workflows in a variety of professional settings. The ability to work with databases effectively is a valuable skill in today’s data-driven world. Salary differs according to the role, key responsibilities, your skillset, and years of experience in the respective domains.