Basic Database Concepts

Last Updated : 11 Jun, 2025

The database system is an excellent computer-based record-keeping system. A collection of data, commonly called a database, contains information about a particular enterprise. It maintains any information that may be necessary for the decision-making process involved in the management of that organization.

It can also be defined as a collection of interrelated data stored together to serve multiple applications. The data is stored in a way that is independent of the programs that use the data. A generic and controlled approach is used to add new data and modify and retrieve existing data within the database. The data is structured to provide the basis for future application development.

Purpose of Database

The intent of a database is that a collection of data should serve as many applications as possible. Therefore, a database is often thought of as a repository of information needed to run certain functions in a corporation or organization. It would permit not only the retrieval of data but also the continuous modification of data needed for the control of operations. It may be possible to search the database to obtain answers to questions or information for planning purposes.

In a typical file-processing system, permanent records are stored in different files. Many different application programs are written to extract the records and add the records to the appropriate files. However, this scheme has several major limitations and disadvantages, such as data redundancy (duplication of data), data inconsistency, maladaptive data, non-standard data, insecure data, incorrect data, etc. A database management system is an answer to all these problems as it provides centralized control of the data.

Database Abstraction

A major purpose of a database is to provide the user with only as much information as required by them. This means that the system does not disclose all the details of the data rather it hides some details of how the data is stored and maintained. The complexity of databases is hidden from users, which is ordered through multiple levels of abstraction to facilitate their interaction with the system. The different levels of the database are implemented through three layers:

1. Internal Level(Physical Level): It is the lowest level of abstraction closest to physical storage. It describes how the data is stored concretely on the storage medium.

2. Conceptual Level: This level of abstraction describes what data is concretely stored in the database. It also describes the relationships that exist between the data. At this level, databases are described logically in terms of simple data structures. Users at this level are not concerned with how these logical data structures will be implemented at the physical level.

3. External Level (View Level): This level is closest to users and is related to the way the data is viewed by individual users.

Since a database can be viewed through three levels of abstraction, any change at one level should not directly affect the other levels. As databases continue to grow, there may be frequent changes to them sometimes. This should not lead to redesign and re-implementation of the database. In such a context the concept of data independence proves beneficial.

Concept of Database

To store and manage data efficiently in the database let us understand some key terms:

1. Database Schema: It is a blueprint or structure of the database that defines the organization of data, types of data that will be stored in rows and columns, constraints, and relationships between tables.

2. Data Constraints: In a database, we can set rules to specify what kind of data can be stored in each column of a table. These rules are called constraints. They help ensure the data is valid and follows certain guidelines. Constraints are defined while we are creating or modifying a table.

3. Data dictionary or Metadata: Metadata is known as the data about the data. The database schema along with different types of constraints on the data is stored by the DBMS in the dictionary known as the data dictionary.

4. Database instance: In a database, a database instance is used to define the complete database environment and its components. It consists of a set of memory structures and background processes that are responsible for accessing and managing the database files.

5. Query: In a database, a query is used to access data from the database. Users have to write SQL queries to retrieve or manipulate data from the database.

6. Data manipulation: In a database, we can easily manipulate data using the three main operations that is Insertion, Deletion, and updation.

7. Data Engine: It is an underlying component that is used to create and manage various database queries.

Advantages of Database

Let us consider some of the benefits provided by a database system and see how a database system overcomes the above-mentioned problems:

Reduces database data redundancy to a great extent
The database can control data inconsistency to a great extent
The database facilitates sharing of data across applications and users.
Database enforce standards to ensure uniformity.
The database can ensure data security through user permissions and access control .
Integrity can be maintained through constraints and referential integrity.

Therefore, for systems with better performance and efficiency, database systems are preferred.

Disadvantages of Database

With the complex tasks to be performed by the database system, some things may come up which can be termed as the disadvantages of using the database system. These are:-

Security may be compromised without good controls.
Integrity may be compromised without strong enforcement of constraints.
Extra hardware may be required for managing large databases.
Performance overhead may be significant, especially with complex queries or large amounts of data
The system is likely to be complex which requires skilled professionals to manage and maintain.

Normalization

Normalization is the process of organizing a database to minimize redundancy and dependency by breaking down complex tables into smaller, more manageable ones. It is important to understand normalization because it helps you create efficient and scalable databases, reduces data inconsistency and duplication, and makes it easier to update and maintain the database over time.

Normalization helps in improving the structure of the database by applying certain rules (like 1NF, 2NF, 3NF, BCNF) that eliminate unwanted relationships and dependencies. This ensures that each piece of information is stored in only one place, making updates simpler and reducing data anomalies.

Conclusion

Databases are essential for efficiently managing and organizing data, ensuring consistency and security. By using techniques like normalization and constraints, databases minimize redundancy and ensure data integrity. While they offer significant benefits, such as improved performance and data sharing, they also come with complexities. Understanding these core concepts is crucial for building scalable and efficient systems.

Basic Database Concepts

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Article Tags :

Basic Database Concepts

Purpose of Database

Database Abstraction

Concept of Database

Advantages of Database

Disadvantages of Database

Normalization

Conclusion

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