NoSQL is a non-relational database used to retrieve and store info by other means other than relations which is synonymous with relational databases.
In simple terms, databases that store and retrieve info using other modeling techniques apart from tabular relations.
Many NoSQL databases are available, but today I am going to list 15 best NoSQL databases in my opinion.
MongoDB is an object-oriented, dynamic, scalable and simple NoSQL database based on the document store model.
Expect no columns and rows as you would see in a relational database, objects are stored as a separate document under one collection.
Apache Cassandra is an open-source was designed to handle big data across the servers with high availability, high performance, and high scalability.
Redis is an open-source database, in-memory key-value with the optional duration with NoSQL.
Data structures supported by Redis include; String, Lists, Sets, Queries, Bitmaps, Geospatial indexes with radius queries and hyper logs.
CouchBase is an open-source NoSQL database, distributed and multi-model document-oriented package optimized for interactive apps.
Learn CouchBase from the official website tutorials and documentation
Apache HBase is an open-source non-relational and a distributed database which is modeled for big table data from Google, and it was written in Java.
It is capable to host billions of rows by millions of columns, and you may add servers to increase capacity, add master nodes to improve high availability of data.
It also comes with simple API which utilizes Java for customer access.
Graph Base NoSQL Database6.
Graph Base NoSQL Database uses perfect graphical representations ideal for scalability.
It utilizes graphic structures with edges, nodes, and properties which are index-free adjacency.
You can easily transform data from a model to the other. Nodes and edges are used to represent and store data organized by relationships and represented with edges between nodes. Nodes and relationships have defined properties.
Oracle NoSQL Database7.
Oracle NoSQL Database is an open-source NoSQL database distributed with key-value.
It uses Oracle Berkeley DB Java Edition HA storage engine client-server which provides single-master and database multi-replication. It provides latency-sensitive apps and services in large volume.
It is horizontally scalable, sharding and replicas, with a high-availability fault-tolerance. Learn oracle NoSQL
Riak NoSQL Database8.
Riak is a NoSQL database, open-source & enterprise versions available in the cloud version. It is easy to deploy and scale with high availability. You can choose to add nodes seamlessly to the cluster. Its powerful features like link walking and map/reduce can accommodate complex queries.
Riak supports Erlang API and protocol buffer in addition to HTTP API. Its API supports GET, PUT, POST and DELETE to receive, update, create and delete objects respectively.
Riak is highly fault-tolerant, high availability and supports query and predictable latency.
Its keys/values can be stored in memory, on a disk or both.
OrientDB: Graph Database9.
It is an open-source NoSQL database with native graphics and multi-model support.
It supports document full text, very responsive, key-value and document, it is also object-oriented.
It is written in java hence very fast and can store 220,000 records/second approximately on regular hardware, also supports ACID transaction processing for document databases.
It is an open-source database, high performance and distributed memory caching system with the intention to speed dynamic web applications by reducing their database load.
It uses a NoSQL database model which allow documents, graphics, and columns among its data models.
It is a distributed native graph database that implements a graphical model top-down to the storage level.
SleekDB is a NoSQL database which stores data in plain JSON files.
Simply not designed for heavy-load I/O operations, works best for low to medium traffic websites of less than 100,000 number of traffic.
It has features like; lightweight and faster, schema-free storage, can query on nested properties, dependency-free, default caching layer, cross-platform and more.
UnQLite is an in-process library that implements self-contained server-less and zero-configuration and transactional NoSQL database engine.
UnQLite is a document store database like MongoDB, Redis, etc.
A unique feature in UnQLite is its ability to write and read on ordinary disk files.
It is a cross-platform database hence can copy database freely across 32 and 64 bit systems also between big-endian and little-endian.
DBreeze is a professional database which is an open-source and multi-paradigm database that is multi-threaded and ACID compliant. It cuts across servers, desktops mobile, and IoT.
DBreeze was made with C# language.
NoSQL database types are divided into four; document databases – pairs each key with a complex structure called document, in a document you will get key-array pairs or key-value pairs and nested in documents. Key-value stores – where every item is stored as a pair. Wide – column stores- are optimized for querying large data sets and instead of rows, columns of data are stored together. Graph stores – store information about graphs and network connections, for instance, social connections. So before deciding on the NoSQL database, kindly check its components and functionalities the first thing.