A relational database is a type of database in which data is organized into tables, and these tables are linked based on the data shared by each of them. This structure allows you to perform flexible complex queries on many tables at the same time.
The structure of a relational database
A relational database consists of several key components:
- tables. These are the building blocks of a relational database. Each table contains data about a specific object, such as customers or products;
- fields. These are different categories of data in each table, such as “name” or “email”;
- records. These are separate entries in the table. Each record includes a unique key, known as the primary key, which identifies this record;
- relationships. These are relationships between tables established using shared data known as foreign keys.
Relational and non-relational databases: a comparative study
While relational databases organize data into tables, non-relational databases, also known as NoSQL databases, do not rely on a tabular structure and use a variety of data models, including document, graph, key-value, and wide column.
Relational databases are best suited for processing structured data and complex queries. Non-relational databases are better suited for processing large amounts of diverse, rapidly changing data.
The relational database engine
Relational databases work based on the principles of the relational model proposed by E. F. Codd in 1970. This model is based on mathematical set theory and uses Structured Query Language (SQL) for database queries and maintenance.
The impact of relational databases on business
Relational databases have a huge impact on business. They provide a highly efficient, flexible and secure system for storing and retrieving data. They maintain ACID properties (atomicity, consistency, isolation, durability), ensuring the reliability of transactions. They also offer robust security features, including access control, browsing, and backup.
Leading Relational database systems
Several Relational Database Management Systems (RDBMS) are available today. Some of the most popular include:
- the Oracle database. It is known for its multifunctional platform and scalability;
- MySQL. It is popular due to its ease of use and open source code;
- Microsoft SQL Server. Recommended for its deep integration with other Microsoft products;
- PostgreSQL. It is appreciated for its compliance with SQL standards and extensibility.