What are non-relational databases?

Non-relational databases include: 1. MongoDB, which is a document-oriented open source NoSQL database; 2. Cassandra, which was developed by Facebook for inbox search; 3. Redis, which is the most famous key-value store .

What is a NoSQL database?

NoSQL database (non-relational database) is a non-relational database system used to store and retrieve data. In today's world we should not just store all data in tabular format without predefined fixed schema (fixed without columns). Like user-generated data, geolocation data, and IoT-generated data, social graphs are an example of the exponential growth of real-world data. These huge amounts of data also require a lot of processing. This is when NoSQL databases appeared. Using NoSQL databases, we can store and retire file, key-value, graph-based data easily and faster. We can easily avoid complex SQL join operations. Easily scale horizontally with NoSQL DBs for real problems (web and enterprise business applications). Carlo Strozzi introduced the term NoSQL in 1998. Motivations for using NoSQL – Simplicity of design, horizontal scaling to clusters of machines

NoSQL Database Types

Document Databases – These databases typically associate each key with complex data called a document Structural pairing. Documents can contain key array pairs, key-value pairs, or even nested documents. Examples: MongoDB, Apache CouchDB, ArangoDB, Couchbase, Cosmos DB, IBM Domino, MarkLogic, OrientDB.

Key-value storage - Each individual item is stored as a key-value pair. Key-value stores are the simplest of all NoSQL databases. Examples: Redis, Memcached, Apache Ignite, Riak.

Wide Column Stores - These types of databases are optimized for queries on large data sets and store columns of data together instead of rows. Examples: Cassandra, Hbase, Scylla.

Graph storage - These store information about graphs, networks, such as social relationships, road maps, transportation links. Examples: Neo4j, AllegroGraph.

2019Best NoSQL Database

MongoDB: is a document-oriented open source NoSQL database. MongoDB uses JSON-like documents to store any data. It is written in c.

Cassandra: Developed by Facebook for inbox search. Cassandra is a distributed data storage system for processing large amounts of structured data.

Redis: is the most famous key-value store. Redis is written in C language. It is licensed under BSD.

HBase: It is a distributed non-relational database designed by Google for the BigTable database.

Neo4j: Called a native graph database because it effectively implements the property graph model, all the way to the storage layer.

Oracle NoSQL: Implemented mapping from user-defined keys to opaque data items.

Amazon DynamoDB: Uses a NoSQL database model that is non-relational, allowing documents, graphs, and columns among its data model.

Couchbase: is a NoSQL document database for interactive web applications. It has a flexible data model, is easily extensible, and provides consistent high performance.

Memcached: is an open source, high-performance, distributed memory caching system designed to accelerate dynamic web applications by reducing database load.

CouchDB: It is an open source NoSQL database that uses JSON to store information and JavaScript as the query language.

Recommended tutorial: "sql tutorial"

The above is the detailed content of What are non-relational databases?. For more information, please follow other related articles on the PHP Chinese website!