Data storage is essential for software. Whether to store customer, company, transaction data, among other important items, it is necessary to have a database for this important mission.

And although many database models exist today, the relational database still stands out for a number of factors.

Whether because of their working structure, or because of the integrity of data storage and retrieval, relational databases bring important characteristics to the developer — and also to the user.

So, if you want to know what the relational database is and how it works, be sure to keep reading the special content we’ve prepared below:

What is and how does a relational database work?

A relational database is a database model that connects information based on logical relationships. These logical relationships are made possible through tables, which store data in a simple, easy-to-understand structure.

In practice, tables work like an Excel spreadsheet. Rows are unique records — which use their own identifier — while columns are identifying attributes of the information.

For example, we have the table to represent a dog:

Note that each line is represented by a unique identifier (positioned in column “A”, ), as well as attributes that describe the characteristics of the animal (column “B” to column “E”). Based on this, it is possible to store information securely and, when necessary, retrieve it quickly and efficiently.

Obviously, a database can contain many tables with unique attributes. In the case presented here, we only have one table for dogs, but we could have another table designed for cats, birds, feed and even data from the responsible veterinarian – if it is a structure of a veterinary clinic, for example.

What is a Relational Database Management System (RDBMS)?

While the relational database represents a database functioning model, the Relational Database Management System is what enables the functioning of the entire information storage structure.

In practice, RDBMS brings all the functions that allow the use of the database in order to extract its invaluable advantages. Examples of RDBMS are:

• PostgreSQL;

• MySQL;

• Oracle;

• SQL Server;

• Firebird.

That said, let’s get to know the basic functions of these management systems.

Basic Functions of the Relational Database Management System

Although there are some characteristics of their own, Relational Database Management Systems have some basic functions to work. Below, we list 5 of them for you to understand how the RDBMS works:

1. Create relationships between tables

As we talked about at the beginning of the content, tables are the main elements of a relational database. But, alone, they cannot generate value for the systems and, consequently, the user.

Therefore, the RDBMS is the tool that allows the connection between them, enabling the data to be structured in logical relationships for the business. Thus, the possibility of creating relationships between tables is one of the basic functions of RDBMS.

2. Insert, delete, edit or copy data

Another important function provided by RDBMS is the complete manipulation of data contained in a table. Whether inserting, deleting, editing or copying data, the RDBMS must offer these options to the user.

3. Query data stored in tables

In the same way that full data manipulation is provided by a RDBMS, simple data query is also a function present in the system. And here we’re talking about simple queries — which involve just one table — or more complex queries, which involve multiple tables within the database

4. Manage users

Database user management is also performed by RDBMS. Here, at a deeper level, the system has access control to organize who can create tables, relationships between them or even perform configurations and optimize the database.

This is a security feature to prevent data manipulations by unauthorized and/or unprepared users.

5. Import and export data

Finally, we have the option of importing or exporting data from a database, a task that RDBMS is also capable of doing. So, whether to introduce a large amount of data into the database, or to export the information to another location, the management system — usually — offers this option.

Features, advantages and disadvantages of the RDBMS

Despite being a robust structure, it is important to understand that a Relational Database Management System has its own characteristics, advantages and disadvantages in use.

So, let’s understand more about these RDBMS points:

Furthermore, we have coupling as one of the main problems of the relational database. Coupling shows how dependent one object is on another, which can result in unanticipated changes in all the parts that are in that dependency.

In other words, in some cases, a database change may result in the need to modify application code, test codes and even project documentation. So, depending on the coupling level, it can cause a big headache for the devs.

To get around this problem, it is necessary to delve into the world of RDBMS to understand how it is possible to extract the most from their functionalities, based on their characteristics and behavior.

Thus, with in-depth knowledge of the manager you use, it will be possible to create better systems for users, in addition to making the work of system developers easier.

Did you like the content? Also read: Relational and non-relational database: types, characteristics and how to choose