What is Non-relational Database?

Web Development Jargons Explained in 5 Different Ways

TLDR: A non-relational database is a type of database structure that organizes data in collections ("Books") of data entries ("Moby-dick", "War and peace"). Entries are not restricted to the attributes they can have. One book can have "year of publish" and "genre", whereas another book can have "year of publish" and "ISBN".

Explain like I only speak in plain English

A non-relational database is a type of database structure that organizes data in collections ("Books") of data entries ("Moby-dick", "War and peace"). Entries are not restricted to the attributes they can have. One book can have "year of publish" and "genre", whereas another book can have "year of publish" and "ISBN".

Non-relational database is known for its flexibility and speed, and popular amongst early stage startups. However, flexibility can also lead to consistency issues if you are not careful.

Non-relational database is also referred to as NoSQL database because of SQL's relationship with relational databases.

Explain like I'm a total nerd

Non-relational database was created to overcome the pitfalls of relational database. Especially its limitation in dealing with fast changing data structures. Relational database have rigid data structures and are difficult to edit quickly. Modern web startups often have to modify their data structures to follow the demand of its users.

Non-relational database stores data entries in collections, which is analogous to tables in a relational database. However, non-relational database stores each entry as key value pairs, instead of a row and column structure. This gives a great freedom of customizability to the attributes each entry can have.

The below two entries represent two books in a book collection. Each entry can contain different attributes.

{
  ISBN: 820938494832,
  title: "A Man's Day",
  author: "Tony Storm",
  publisher: "a12b3"
}

{
  ISBN: 820938498901,
  title: "To Hell and Back",
  author: "Rachel Stevens",
  price: "20.15",
  description: "A fiction about love in the after life.",
  publisher: "a12b3"
}

An attribute can be used to store an identifier belonging to data of other collections. We can store the publisher's identifier number as an attribute of each book to add the relationship between a book and its publisher.

Non-relational databases are used by many web giants such as Google, Facebook, Amazon.