The Complete Guide to Relational Database Management System (RDBMS)

Relational Database Management System

The Complete Guide to Relational Database Management System (RDBMS)

Key Points:

  • A relational database is special because they have the ability to identify and access data in relation to other data, usually via data tables.
  • Relational Database Management Systems (RDBMS) allow users to store, manage and analyze their data in a way that is both efficient and structured. This saves a lot of time and work, especially for businesses, governments, and other organizations.
  • Unique primary keys are used to track and recall data tables, and a robust database system can maintain many tables.
  • Edgar F. Codd from IBM created the first form of database normalization in 1970. His work laid the groundwork for modern RDBMS and has been instrumental in the growth of the information technology industry.

Relational Database Management Systems (RDBMS) are software applications designed to manage, store, and retrieve data using a set of predefined rules and tables. They are the preferred choice for businesses, organizations, and governments due to their ability to efficiently store and retrieve large amounts of structured data. RDBMSs use a structured query language such as SQL to interact with data and provide a flexible platform for managing complex data relationships. These systems also ensure data consistency by implementing constraints, eliminating duplication and ensuring referential integrity.

What is RDBMS: Complete Explanation

Data is internet gold. It can be anything from statistics to names to locations. Everything that flows through the internet is data, even games. Each piece of data is valuable in its way. In order to make use of this data, it has to be stored, parsed, and made accessible. Structurally organized data stored in a computer is known as a database. This can be anything from a text file to an Excel spreadsheet.

Databases are incredibly useful for research, marketing, testing, and security. They are even more useful as relational databases. A relational database is the same as a regular database with the additional ability to identify and access data in relation to other data. This is most commonly done through data tables.

Employers may use a relational database to manage employee information. For example, the company may wish to know the birth dates, ages, place of birth, certification status, length of employment, and any other pertinent information of its employees. These information types become the column titles across the top of the spreadsheet. Then, each employee can be added as a row. Like this:

NameDate of Birth Place of Residence Certified Years Employed
Carl02/17/1987Glendale, CATrained4
Boyles06/21/1996Seattle, WAUntrained2
Jenny04/15/1994Houston, TXTrained4

This table relates specific information to each subject. This allows the user to search through information and gather like data through what is known as a relational database management system. This allows the user to manipulate and search through information for a multitude of administrative purposes. Here are a few examples of what a user may use an RDBMS for:

  • Cross-reference datasets
  • Quickly fill in and duplicate information such as contacts
  • Track and update employee records
  • Monitor and compare research results
  • Scalability of data tracking
  • Data Safety – program safety features that preserve database entries
  • Fault Tolerance – keeps copies of the database
  • Increase the speed of administrative tasks
  • Store sensitive data
  • Provide multiuser access

RDBMS: An Exact Definition

RDBMS is short for Relational Database Management System. It is the software method used for structurally organizing, viewing, searching, creating, updating, deleting, and manipulating the data tables in a relational database. Most relational database management systems make use of the structural query language (SQL).

Relational Database Management systems are a subset of database management systems. The difference is that RDBMS specifically manages relational databases. Relational databases are used to record information related to a specific entity. A common example of a relational database would be a human resources contact list. The information is stored in a table with a set of information (e-mails, phone numbers, references, and employee names).

Relational Database Management System
RDBMS is short for Relational Database Management System. It is the software method for structurally organizing, viewing, searching, creating, updating, deleting, and manipulating the data tables in a relational database.

How Does RDBMS Work?

Relational Database Management Systems like Oracle DB or MySQL store data in relational databases or data tables. A full database system can have as many tables as the system can handle. Each table is recognized and tracked by a unique primary key.

Each table is made of rows and columns. The rows are used as a record while the columns are used to separate between fields. You can view the previous table example to understand this better. Each row contains cells of information that are related to a single entity. In the above example, each entity was a person. The cells following in each row are different pieces of data, or records, attributed to the entity. This system of rows and columns allows the table to be parsed, searched, updated, and modified easily.

People who work with databases often find that their collection of data grows exponentially and becomes rather burdensome to deal with. Manual changes to individual cells that need to be repeated throughout a dataset and even other datasets can take days. With an RDBMS, these changes can be made quickly and in groups with the use of structured query language (SQL).

SQL is a high-level programming language that has syntax similar to the English language. While not every RDBMS uses SQL, most do.

How Do You Create RDBMS?

In order to create an RDBMS, there are a few steps to take.

1. Define the Purpose of the Database

Information is rarely useful when it is gathered without a purpose. Even if you are creating an RDBMS for educational purposes, you will need to define what you are creating a database of. You’ll need to know what you are gathering, why you are gathering it, and what you are going to do with the information. This will help you organize what kind of information to gather.

2. Get the Data, Create the Structure, and Assign the Primary Keys

Now that you know what you are putting in the database, you’ll need the information. How you get that information may vary and is entirely up to you. As you gather the data, divide it into subject-based tables. One column of each table you create will be used as the primary key. For example, a database of employees will often use the employee name or identification number as the primary key. This helps to prevent duplicate rows and creates unique identifiers for each entity. If the database you are creating is not using names, then you’ll need to identify a column that will continue entirely unique values to call to. The primary key will be used as the index for quick search and retrieval.

3. Create Relationships between Tables

If the databases’ tables are unrelated to each other, they will not be very useful. To create a functional database, each table needs to be related to the other. There are three different types of relationships that can be established.

  • One-to-Many – One table relates to many tables. This is useful when dealing with hierarchical structures. For example, one table may be a list of managers with information about the managers stored on it (like names, addresses, phone numbers, and email). Each manager also has a series of employees or responsibilities under them. So a series of tables can be created that lists the different stores of information for each group.
  • Many-to-Many – Each table relates to other tables through a junction table. This means that one table of a list of products and one table with a list of orders can be related by using a third table to reference information from each, for this example that table would be order details.
  • One-to-One – Each table contains a similar primary key with different data sets. This can be useful when one table needs to remain private while one is used to being on display or when separating product stock information from product details.

4. Refine the Design

Once you’ve gathered and organized enough information, you’ll begin to form better structural ideas for your tables. Refine the design and structure to improve performance. This is just down to good old-fashioned trial and error.

Who Created RDBMS?

Databases have been around as long as people have been able to keep records. In the early rise of computing technology, a computer scientist from IBM by the name of Edgar F. Codd introduced a new way to model data. In his paper, “A Relational Model of Data for Large Shared Banks”, published in June of 1970, Edgar described a way of creating cross-linked tables that would allow for any piece of data to be stored once. With his structure, a large enough database could answer any question as long as the information is stored within one of the cross-linked tables.

database normalization
Edgar F. Codd established the first form of database normalization.

It took nine years before the first commercial relational database was released by Oracle. It was quickly followed by the release of IBM’s DB2, SAP Sybase ASE, and Informix. The idea quickly caught on as the 80s and 90s saw the incredible growth of the use of relational databases.

What Are the Applications of RDBMS?

Relational Database Management Systems have been in use for managing databases across the world by almost every company that used modern technology. Data is a digital representation of anything. Thus, every company with an online presence or modern transaction system makes use of a database for their business. Just as well, managing workforce payroll, time clock, and certifications are done efficiently through RDBMS as well.

It’s hard to pinpoint exact examples of the purpose of RDBMS because the purpose of data is so vast. Instead, here is a list of different possible applications of RDBMS:

  • Business management
  • Business reporting
  • Financial reporting
  • Marketing
  • Research
  • Club membership
  • Client management
  • Event ticket management

Even this list can refer to any number of specific uses in businesses or organizations. The beauty of data is that its uses are constantly expanding. The easiest way to describe what RDBMSs can be applied to is this: any purpose that collects and uses data. That describes just about everything from music playlists to library management.

Relational Database Management System
Here is a depiction of the structure of a relational database, which gives you a basic idea of how complicated the data would be with it!

Examples of RDBMS in the Real World

Cloud-computing and smart technology have pushed the need for RDBMS use across the board. Like any other technology or concept, there are many different variations. Below are descriptions of some of the most popular RDBMSs in use today:


As an open-source SQL, MySQL is incredibly popular. Its open access is often employed for web development through PHP. MySQL is the go-to option for an inexpensive and reliable solution to database management. It has been in existence since 1995. Due to Its age, it has a rather large community of developers to draw information from.

MySQL has been acquired by Oracle which unfortunately led to a serious drop in open source development. Because Oracle has not put the effort into updating and maintaining the open-source development of MySQL, it lacks advanced features that some developers may be accustomed to.


  • Inexpensive
  • Reliable
  • Large community


  • Poor performance when scaling
  • Lacks advanced features
  • Owned by Oracle


PostgreSQL is another open-source SQL database. It is still open source and free from corporate control. Like MySQL, it is mainly used for web application development. PostgreSQL is a surviving open-source SQL database from the early development days of database management.

There aren’t many differences between MySQL and PostgreSQL besides performance. PostgreSQL is known to be a slower, or less efficiently compiled, system. Unlike MySQL, PostgreSQL was never acquired by a larger company. Thus, it is still operating as an inexpensive database option with open-source code.

Another similarity to MySQL is the size of the community of developers. It doesn’t have as large a community as MySQL, but it has been around long enough that the community is helpful and experienced.


  • Open source
  • Inexpensive
  • Helpful community
  • Additional Features (foreign key support)


  • Slower performance
  • Poor scalability

Oracle DB

Oracle DB is owned by the Oracle Corporation. It is not open-source software. Many speculate that the acquisition of MySQL by Sun Microsystems, now Oracle Corporation, was intended to give them the upper hand in RDBMS software. The lack of open-source development on MySQL since its acquisition by Sun Microsystems seems to be evidence of this.

Now Oracle DB is used in most of the top banks in the world. The integrated business applications and powerful technology offered by Oracle are perfect for the secure management of databases. Oracle DB even contains essential functionality built especially for banks to utilize.

Oracle sells everything from Cloud systems to financial and marketing support.

Oracle is an expensive RDBMS solution. Rightly so. It boasts a series of features that place it as one of the best-performing RDBMS in use.


  • Advanced features
  • Specialty business functions
  • Security through obscurity (non-open source software)


  • Expensive service
  • Closed source code
  • Database paired with Oracle technology

SQL Server

As a leader in enterprise software solutions, Microsoft offers a database management system native to Windows and compatible operating systems. SQL Server is much like Oracle DB. It is a closed-source software. Some functions are built for specific business needs.

SQL Server is among the top performers in the database management category. It is much more reliable for large enterprise applications, which is why most companies who handle massive amounts of database archives will utilize SQL Server.

In tradition with many of Microsoft’s software offerings, there is a lighter, entry-level version that can be used for free named Express. For smaller database applications, Express might be enough to handle it. If the database begins to exceed the ‘free’ features of SQL Server in Express, you’ll likely begin to purchase extra functionality that can quickly become expensive. However, It’s hard to argue with the functionality Microsoft’s applications offer.


  • Efficient for large enterprise
  • Natively developed for Windows enterprise
  • Free version available (Express)
  • Feature-filled


  • Expensive


SQLite is yet another open-source database. It is incredibly popular due to it being free, but also because it can store an entire database in a single file. This is useful for creating and maintaining a light database without the need to connect to a server. In other words, SQLite is a portable solution.

Common smart devices like smartphones, PDAs, iPods, cable or satellite boxes, and other electronics use SQLite to manage their smaller databases. SQLite is also the go-to SQL database for learning the commands and functions of an RDBMS.


  • Free
  • Open Source
  • Saves database as single file
  • Lightweight


  • Fewer SQL commands available
  • Does not scale well

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Frequently Asked Questions

What is RDBMS?

RDBMS is the software system implemented to organize, update, view, search, delete, and otherwise manipulate Relational databases. For more information read above to get a better RDBMS definition.

What does RDBMS stand for?

RDBMS is an acronym for a relational database management system.

What is RDBMS in SQL?

Relational Database Management systems in SQL are the method of structuring, organizing, creating, viewing, updating, or otherwise manipulating Relational databases.

What is the difference between RDBMS VS NoSQL?

In the recent decades of growth in information technology and smart devices, the need for non-relational databases has also grown. NoSQL is a non-relational database management system. It can still be used for transaction-oriented applications (OLTP) which is what often leads to confusion. NoSQL is more useful when dealing with multiple or new data types rather than data in relation to other data. It has been said that NoSQL is for scaled OLTP and JSON documents, while RDBMS is for enterprise OLTP or databases smaller than 1 terabyte.

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