What are the Most Popular Relational Databases

Relational database management systems are the most popular form of database management systems (DBMS) that includes Oracle, SQL Server, MySQL, and DB2. This article lists the most popular RDBMSs in the world.

A relational DBMS (RDBMS) stores data in a tabular form where a column represents a property and each row in a table represents a record.
 
RDBMSs allow Create, Read, Update, and Delete (CRUD) operations. Structured Query Language (SQL) is the language that is used to query, update, and delete data in relational database management systems (RDBMS). SQL is a standard query language. SQL language’s queries are also known as SQL commands or SQL statements.
 
RDBMS
If you’re new to SQL, here is a good article, SQL for Beginners.
 
Here is the list of top 10 most popular RDBMSs are:
  1. Oracle
  2. MySQL
  3. SQL Server
  4. PostgreSQL
  5. IBM DB2
  6. Microsoft Access
  7. SQLite
  8. MariaDB
  9. Informix
  10. Azure SQL

1. Oracle

 
Oracle developed by Oracle Corporation is the most popular relational database system (RDBMS). Not only Oracle is a RDBMS, but also provides functionality for Cloud, Document Store, Graph DBMS, Key-value storage, BLOG, and PDF Storages. Recently. Oracle just announced autonomous feature that allows database to be intelligent and self-managed.
 
The current version of Oracle Database is 18c.
 
Oracle database is a relational database (RDBMS). Relational databases store data in a tabular form of rows and columns. Column of a database table represents the attributes of an entity and rows of a table stores records. An RDBMS that implements object-oriented features such as user-defined types, inheritance, and polymorphism is called an object-relational database management system (ORDBMS). Oracle Database has extended the relational model to an object-relational model, making it possible to store complex business models in a relational database.
 
One characteristic of an RDBMS is the independence of physical data storage from logical data structures.
 
In Oracle Database, a database schema is a collection of logical data structures, or schema objects. A database user owns a database schema, which has the same name as the user name.
 
Schema objects are user-created structures that directly refer to the data in the database. The database supports many types of schema objects, the most important of which are tables and indexes.
 
A schema object is one type of database object. Some database objects, such as profiles and roles, do not reside in schemas.
 

2. MySQL

 
MySQL is world’s most popular database that is open source and free. MySQL was acquired by Oracle as a part of Sun Microsystems acquisition in 2009.
 
In MySQL, the SQL part of “MySQL” stands for “Structured Query Language”. SQL is the most common standardized language used to access databases. Depending on your programming environment, you might enter SQL directly (for example, to generate reports), embed SQL statements into code written in another language, or use a language-specific API that hides the SQL syntax.
 
Key properties of MySQL: 
  • MySQL is a database management system.
  • MySQL databases are relational.
  • MySQL software is Open Source.
  • The MySQL Database Server is very fast, reliable, scalable, and easy to use.
  • MySQL Server works in client/server or embedded systems. 

3. SQL Server

 
SQL Server database developed by Microsoft is one of the most popular databases in the world. Initially launched in 1989 and written in C, C++, SQL Server is now widely used among major companies. SQL Server is also a part of Microsoft’s Azure cloud as Azure SQL Server. The current version of SQL Server is SQL Server 2019.
 
Similar to Oracle and MySQL, SQL Server is also a relational database management system (RDBMS).
 
Some popular SQL Server editions are:
  1.  Azure SQL Database is the cloud-based version of Microsoft SQL Server, presented as a platform as a service offering on Microsoft Azure.
  2. Compact (SQL CE), the compact edition is an embedded database engine. Unlike the other editions of SQL Server, the SQL CE engine is based on SQL Mobile (initially designed for use with hand-held devices) and does not share the same binaries. Due to its small size (1 MB DLL footprint), it has a markedly reduced feature set compared to the other editions. For example, it supports a subset of the standard data types, does not support stored procedures or Views or multiple-statement batches (among other limitations). It is limited to 4 GB maximum database size and cannot be run as a Windows service, Compact Edition must be hosted by the application using it. The 3.5 version includes support for ADO.NET Synchronization Services. SQL CE does not support ODBC connectivity, unlike SQL Server proper.
  3. SQL Server Enterprise Edition is the main database most companies buy that comes with every product feature.
  4. SQL Server Developer Edition includes the same features as SQL Server Enterprise Edition, but is limited to one license only that is used for development purposes by software developers.
 

4. PostgreSQL

 
PostgreSQL is a powerful, open source object-relational database system that uses and extends the SQL language combined with many features that safely store and scale the most complicated data workloads. The origins of PostgreSQL date back to 1986 as part of the POSTGRES project at the University of California at Berkeley and has more than 30 years of active development on the core platform. The current version of PostgreSQL is 11.4 that was released on 20 June 2019. PostgreSQL is written in C language and managed by the PostgreSQL Global Development Group.
 
PostgreSQL is known for its architecture, reliability, data integrity, robust feature set, extensibility, and the dedication of the open source community behind the software to consistently deliver performant and innovative solutions.
 

5. IBM DB2

 
IBM Db2 database is a relational database that delivers advanced data management and analytics capabilities for your transactional and warehousing workloads. This operational database is designed to deliver high performance, actionable insights, data availability, and reliability, and it is supported across Linux, Unix, and Windows operating systems.
 
The Db2 database software includes advanced features such as in-memory technology, advanced management and development tools, storage optimization, workload management, actionable compression, and continuous data availability.
 
With version 11.5, Db2 includes added AI functionality so that businesses can embrace forward-looking data science and AI technologies to retain competitive differentiation. Now you can leverage one platform that is both powered by AI and built for AI to optimize performance and availability while empowering your data scientists to find deeper insights.  
  • Db2 Database can now be purchased as part of the IBM Hybrid Data Management Platform. With a single license, you can change the deployment mix of products at any time, and only get charged for what you use. 
  • Db2 is now powered by AI. It allows you to use machine learning to tune workloads and optimize queries for significantly faster querying.
  • Db2 is fast to deploy and you can get up and running on your laptop within minutes, and start building applications quickly with a full featured database.
  • Db2 supports multiple data types and languages including NoSQL, pureXML, Graph and JSON. You can build in Java, .Net, Ruby, Python, Perl and more.
  • Db2 database is designed for high performance with in-memory technology, storage optimization, and workload management.
  • Db2 provides advanced protection with the help of built-in native encryption with enterprise key management.

6. Microsoft Access

 
Believe it or not. MS Access still remains one of the top 10 databases for local data storages. Access is usually not used in remote or centralized storage. It is used for local small databases.
 

7. SQLite

 
SQLite is a C-language library that implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine. SQLite is the most used database engine in the world. SQLite is built into all mobile phones and most computers and comes bundled inside countless other applications that people use every day.
 
The SQLite file format is stable, cross-platform, and backward compatible and the developers pledge to keep it that way through at least the year 2050. SQLite database files are commonly used as containers to transfer rich content between systems and as a long-term archival format for data. There are over 1 trillion SQLite databases in active use.
 
Key Features Of SQLite: 
  • Transactions are atomic, consistent, isolated, and durable (ACID) even after system crashes and power failures.
  • Zero-configuration - no setup or administration needed.
  • Full-featured SQL implementation with advanced capabilities like partial indexes, indexes on expressions, JSON, common table expressions, and window functions.
  • A complete database is stored in a single cross-platform disk file. Great for use as an application file format.
  • Supports terabyte-sized databases and gigabyte-sized strings and blobs. (See limits.html.)
  • Small code footprint: less than 600KiB fully configured or much less with optional features omitted.
  • Simple, easy to use API.
  • Fast: In some cases, SQLite is faster than direct filesystem I/O
  • Written in ANSI-C. TCL bindings included. Bindings for dozens of other languages available separately.
  • Well-commented source code with 100% branch test coverage.
  • Available as a single ANSI-C source-code file that is easy to compile and hence is easy to add into a larger project.
  • Self-contained: no external dependencies.
  • Cross-platform: Android, *BSD, iOS, Linux, Mac, Solaris, VxWorks, and Windows (Win32, WinCE, WinRT) are supported out of the box. Easy to port to other systems.
  • Sources are in the public domain. Use for any purpose.
  • Comes with a standalone command-line interface (CLI) client that can be used to administer SQLite databases.
 

8. MariaDB

 
MariaDB Server is one of the most popular database servers in the world. It’s made by the original developers of MySQL and guaranteed to stay open source. Notable users include Wikipedia, WordPress.com, and Google.
 
MariaDB turns data into structured information in a wide array of applications, ranging from banking to websites. It is an enhanced, drop-in replacement for MySQL. MariaDB is used because it is fast, scalable and robust, with a rich ecosystem of storage engines, plugins, and many other tools make it very versatile for a wide variety of use cases.
 
MariaDB is developed as open source software and as a relational database it provides an SQL interface for accessing data. The latest versions of MariaDB also include GIS and JSON features.
 

9. Informix

 
IBM Informix® is a fast and flexible database with the ability to seamlessly integrate SQL, NoSQL/JSON, and time series and spatial data. Its versatility and ease of use make Informix a preferred solution for a wide range of environments, from enterprise data warehouses to individual application development. Also, with its small footprint and self-managing capabilities, Informix is well suited for embedded data-management solutions.
 
Key features of Informix includes:
 
Real-time analytics
The single Informix platform helps you power transactional workloads easily in a wide range of environments to enable analytics-driven insights quickly.
 
Fast, always-on transactions
To support mission-critical environments, IBM Informix includes high-availability data replication (HADR), remote secondary standby database servers and shared-disk secondary servers. The flexible grid feature also enables rolling upgrades with no outages.
 
Fewer data management hassles
Informix offers easy deployment features like “smart triggers” that implement event-driven processing and database push notifications, with no schema changes. This allows you to automate your data management and focus on your core business.
 
Simplicity
With a silent installation and small footprint that requires just 100 MB of memory, Informix is simple and non-disruptive. Self-managing capabilities make it ideal as an embedded data management solution. Informix can be up and running in a minute
 

10. Azure SQL

 
Azure SQL Database is a general-purpose relational database-as-a-service (DBaaS) based on the latest stable version of Microsoft SQL Server Database Engine. SQL Database is a high-performance, reliable, and secure cloud database that you can use to build data-driven applications and websites in the programming language of your choice, without needing to manage infrastructure.
 
Key features of Azure SQL includes the following:
 
Fully managed
PaaS database that is always running on the latest stable version of SQL Server Database Engine and patched OS with 99.99% availability.
 
Price/service tiers
Tailor price/performance ratio to your needs with flexible service tiers that span from affordable $5/month to powerful 80-core databases.
 
Scalability
Easily scale up, scale out, or shard your databases depending on your needs to improve performance of your application.
 
Single database
Use the single database managed by a SQL Database server for your SaaS applications and microservices that need a single database with the predictable performances.
 
Elastic pools
SQL Database elastic pools are a simple, cost-effective solution for managing and scaling multiple databases that have varying and unpredictable usage demands.
 
Managed instance
Use the Managed Instance to get a fully managed SQL Server Database Engine Instance hosted in Azure cloud, with minimal or no database code changes needed for migration from on-premises databases.
 
Platform as a Service
Built-in High-availability, automated backups, and geo-replication, will prevent maintenance operations, infrastructure or hardware failures from stopping your business.
 
Advanced security
Secure your database with Azure AD authentication, Virtual Networks, Firewalls, Always Encrypted connections. Identify threats and vulnerabilities with built-in security.
 
Monitoring and tuning
Built-in monitoring and intelligent tuning help you dramatically reduce the costs of running and managing databases and maximizes performance of your application.
 

Next

 
There are several types of database management systems such as relational, network, graph, and hierarchical. Learn here Types of Databases. 

References

 
https://en.wikipedia.org/wiki/Relational_database
https://db-engines.com/en/ranking/relational+dbms
Respective products references