What Are Relational Databases?

Relational databases are, as suggested by the term, collections of related data. Unlike a basic flat file database, which is most often a single, isolated table, a relational database is able to communicate to and from all its tables. Not only does it contain various data tables, but it also provides connections among those tables. For these reasons, they are a dynamic and vital system for any size company.

Anatomy Of A Relational Database
The most basic component of the relational database is the table. If you think of it in terms of a file cabinet, the file cabinet itself is a database, and each table is a folder. The folder contains content that is relevant to the folder's topic. A file cabinet may hold hundreds of folders.

However, the relational version of a database does the file cabinet one better. If you can imagine the prospect of opening a file folder and instantly being able to see any related type of data without having to search for another folder, then you get the idea.

This type of database uses keys to access information. On each table, users can define certain keys that will be accessible during a search query. The keys can either be primary or foreign, depending on their function. A primary key identifies data in a table. A foreign key links two tables together.

SQL is an integral part of the relational database. SQL, short for structured query language, is a special language that adds to, edits and recalls information in a database.

A Brief History
British scientist Edgar Codd is responsible for creating the relational database model as we know it. In the 1970s, he wrote a dissertation known as "A Relational Model of Data for Large Shared Data Banks." This paper indicated the potential of a database that was able to search itself.