Types of NoSQL Database

Types of NoSQL Database

There are four types of NoSQL databases and those are -

1. Key-value store

2. Document store

3. Graph based

4. Wide column store

Let us discuss them in detail.

Key-Value Store

• Key-value pair is the simplest type of NoSQL database.

• It is designed in such a way to handle lots of data and heavy load.

• In the key-value storage the key is unique and the value can be JSON, string or binary objects.

• For example -

{Customer:

|

{"id":1,"name":"Ankita"},

{"id":2,"name":"Kavita"}

|

}

Here id, name are the keys and 1,2, "Ankita", "Prajkta" are the values corresponding to those keys.

Key-value stores help the developer to store schema-less data. They work best for Shopping cart contents.

The DynamoDB, Riak, Redis are some famous examples of key-value store.

Document Based Systems

• The document store make use of key-value pair to store and retrieve data.

• The document is stored in the form of XML and JSON.

• The document stores appear the most natural among NoSQL database types.

• It is most commonly used due to flexibility and ability to query on any field.

• For example -

{

"id": 101,

"Name": "AAA",

"City" : "Pune"

}

MongoDB and CouchDB are two popular document oriented NoSQL database.

Column Based Systems

• The column store model is similar to traditional relational database. In this model, the columns are created for each row rather than having predefined by the table structure.

• In this model number of columns are not fixed for each record.

• Columns databases can quickly aggregate the value of a given column.

• For example -

The column store databases are widely used to manage data warehouses, business intelligence, HBase, Cassandra are examples of column based databases.

Graph Databases

The graph database is typically used in the applications where the relationships among the data elements is an important aspect.

The connections between elements are called links or relationships. In a graph database, connections are first-class elements of the database, stored directly. In relational databases, links are implied, using data to express the relationships.

The graph database has two components -

1) Node: The entities itself. For example - People, student.

2) Edge: The relationships among the entities.

For example -

Graph base database is mostly used for social networks, logistics, spatial data. The graph databases are - Neo4J, Infinite Graph,OrientDB.