The 4 Types of NoSQL Databases You Need to Know
With the modern big data revolution, NoSQL databases have become widely popular. Their scalability and support of unstructured data is appealing to developers seeking solutions outside the traditional structures found in relational databases. And with cloud service providers such as Amazon and Azure introducing their own NoSQL database solutions to the market, it’s no wonder that this approach to database design has been growing in popularity. So we thought it was about time to discuss the importance of NoSQL databases, have a look at different NoSQL database types, and clarify their advantages and limitations.
NoSQL vs RDBMS
Before discussing the NoSQL database types, let’s have a look at how NoSQL differs from traditional relational databases. The following graph illustrates some of the major differences and similarities between the two:
Types of NoSQL databases
There are 4 main categories of NoSQL databases:
Key-value pair
Column-oriented
Graphs based
Document oriented
Each of the above categories has its own features and serves different purposes. As developers, we should understand their features to choose the best option for their products. So, let’s dive into these 4 categories and discuss their features and use cases:
1. Key-Value Pair Based
Key-value pair is the most simple type of NoSQL database. It only has 2 columns, named ‘key’ and ‘value’, where the key can only have string values while the value can store JSON, strings, Blob, XML, etc. The main concept behind this design is to have a hash table with a unique key and a pointer to a data item.
With this simple design, key-value pair NoSQL databases can handle massive data loads and help to store schema-less data.
Key-value pair databases are widely used for:
Session-based applications like shopping carts
Applications with many state changes
Large-scale data handling
For dictionaries and collections
However, key-value pair databases are not the perfect solution if you frequently update the data values or use complex queries.
AWS DynamoDB, Redis, Riak, Memcached, and Scalaris are some of the most used key-value pair NoSQL databases.
2. Column-Oriented
Column-oriented NoSQL databases use a set of columns to store data. These column sets are known as column families, and users can directly query these column families without going through all the data records.
Google’s BigTable paper inspired this database design, and it is capable of handling large data loads on distributed machines. In addition, column-oriented databases provide efficient compression and high performance with aggregated queries such as sum, average, and minimum.
Column-oriented databases are widely used for:
Analytics applications
Data warehouses
Library catalogs
Business intelligence applications
Although column-oriented databases have high standards for performance, it is hard to maintain them strongly consistent since all the columns require multiple write events on disk.
Google BigTable, Cassandra, Hbase, and Hypertable, are examples of some of the most used column-oriented NoSQL databases.
3. Graphs Based
Each data element is stored as a node in graph-based NoSQL databases, and the edges denote relationships between data elements. Each of these nodes and edges has unique identifiers.
Graph-based databases are different from others since there are no tables or columns. However, this model is very flexible and supports scaling across multiple devices. Furthermore, graph-based databases are well ahead in queries with joins in terms of performance compared to relational databases.
Graph-based databases are widely used for:
Social networks
Fraud detection
Knowledge graphs
Logistics handling
However, using a graph-based database is often not ideal as a standalone solution, which is why most graph-based databases are used alongside traditional databases that complement them to serve specific uses.
Neo4J, InfoGrid, Infinite, Graph, and Flock DB, are examples of popular graph-based NoSQL databases.
4. Document-Oriented
Similar to key-value-based databases, document-oriented databases also use key-value pairs. But they store the key-value pairs as documents. Most document-oriented databases support JSON, XML, and BSON document formats.
Query speed and flexibility are the most highlighted features of document-oriented databases. They support nested documents and indexing to improve query speed while allowing developers to make changes to documents as needed.
Document oriented databases are widely used for:
Blogging platforms
CMS systems
Real-time analytics
E-commerce applications
However, using document-oriented databases for an application that requires complex transactions and queries can decrease the application’s performance.
AWS SimpleDB, AWS DynamoDB, CouchDB, MongoDB, OrientDB, and RavenDB are some of the most used document-oriented NoSQL databases.
What else to look out for when choosing a NoSQL database
This article discussed everything you need to know about NoSQL databases, including their features, pros, cons, and 4 main categories of databases available. I hope now you have a good understanding of NoSQL to choose the best database for your project.
However, choosing the correct database is only a part of database administration. You should also pay attention to aspects like risks and security since databases contain a massive amount of sensitive information.
With the rise of cloud services, many organizations have applications alongside databases in the cloud. Although cloud services provide some level of security, you should aim to take your security posture one step further when handling large amounts of data. In our blog, we’re sharing free content to help you learn how to avoid security mistakes, credential leakage, misconfiguration, and data breaches in real-time. Enjoy!