Non Relational Databases can be classified into four major categories such as Key-values database, column database, document database and graph database.
- Key-values database: This is the simplest form of NoSQL database where each value is associated with unique key.
Example : Redis
- Column database: This database is capable of storing and processing large amount of data using a pointer that points to many columns that are distributed over a cluster.
Example : HBase
- Document database: This database can contain many key-values documents with many nested level. Efficient querying is possible with this database. The documents are stored in JSON format.
Example : MongoDB
- Graph database: Instead of traditional rows and columns, this databases uses nodes and edges to represent graph structures and store data.
Example : Neo4J