Structured storage

NoSQL (originally meaning "Not only SQL" or "non-relational") refers to a type of database design that stores and retrieves data differently from the traditional table-based structure of relational databases. Unlike relational databases, which organize data into rows and columns like a spreadsheet, NoSQL databases use a single data structure—such as key–value pairs, wide columns, graphs, or documents—to hold information. Since this non-relational design does not require a fixed schema, it scales easily to manage large, often unstructured datasets. NoSQL systems are sometimes called "Not only S

MongoDB is a source-available, cross-platform, document-oriented database program. Classified as a NoSQL database product, MongoDB uses JSON-like documents (called BSON) with optional schemas. Released in February 2009 by 10gen (now MongoDB Inc.), it supports features like sharding, replication, and ACID transactions (from version 4.0). MongoDB Atlas, its managed cloud service, operates on AWS, Google Cloud Platform, and Microsoft Azure. Current versions are licensed under the Server Side Public License (SSPL). MongoDB is a member of the MACH Alliance.

Redis (; Remote Dictionary Server) is an in-memory key–value database, used as a distributed cache and message broker, with optional durability. Because it holds all data in memory and because of its design, Redis offers low-latency reads and writes, making it particularly suitable for use cases that require a cache.

Free and open-source, distributed, wide column store, NoSQL database management system.

Memcached (pronounced either ["dee/d" being for daemon], or ) is a general-purpose distributed memory-caching system. It is often used to speed up dynamic database-driven websites by caching data and objects in RAM to reduce the number of times an external data source (such as a database or API) must be read. Memcached is free and open-source software, licensed under the Revised BSD license. Memcached runs on Unix-like operating systems (Linux and macOS) and on Microsoft Windows. It depends on the libevent library.

software library providing embedded database for key/value data

document-oriented database

Neo4j is a graph database management system (GDBMS) developed by Neo4j Inc.

is an information system of the company IBM

cloud database provided as a service

open source, non-relational, distributed database system

InfluxDB is a time series database (TSDB) developed by the company InfluxData. It is used for storage and retrieval of time series data in fields such as operations monitoring, application metrics, Internet of Things sensor data, and real-time analytics. It also has support for processing data from Graphite.

key-value database

ScyllaDB is a source-available distributed NoSQL wide-column data store. It was designed to be compatible with Apache Cassandra while achieving significantly higher throughputs and lower latencies. It supports the same protocols as Cassandra (CQL) and the same file formats (SSTable), but is a completely rewritten implementation, using the C++20 language replacing Cassandra's Java, and the Seastar asynchronous programming library replacing classic Linux programming techniques such as threads, shared memory and mapped files. In addition to implementing Cassandra's protocols, ScyllaDB also implem

open-source NoSQL database

RavenDB is an open-source document-oriented database written in C#, developed by RavenDB Ltd. It's built on top of the custom Voron storage engine and supports ACID transactions. RavenDB uses a SQL-like query language, (RQL), and includes native features for handling time series, graph querying, and full-text search. It is cross-platform, supported on Windows, Linux, Mac OS, AWS, Azure, and GCP and can be deployed on cloud, on-prem, and the edge, including constrained environments such as Raspberry Pi Zero. RavenDB can be deployed in distributed clusters with master-master replication.

DuckDB is an open-source column-oriented Relational Database Management System (RDBMS). It is designed to provide high performance on complex queries against large databases in embedded configuration, such as combining tables with hundreds of columns and billions of rows. Unlike other embedded databases (for example, SQLite) DuckDB is not focusing on transactional (OLTP) applications and instead is specialized for online analytical processing (OLAP) workloads. The project has over 6 million downloads per month.

managed database service

analytical database software

OrientDB is an open source NoSQL database management system written in Java. It is a Multi-model database, supporting graph, document and object models, the relationships are managed as in graph databases with direct connections between records. It supports schema-less, schema-full and schema-mixed modes. It has a strong security profiling system based on users and roles and supports querying with Gremlin along with SQL extended for graph traversal. OrientDB uses several indexing mechanisms based on B-tree and Extendible hashing, the last one is known as "hash index". Each record has Surrogate

ClickHouse is an open-source column-oriented DBMS (columnar database management system) for online analytical processing (OLAP) that allows users to generate analytical reports using SQL queries in real-time. ClickHouse Inc. is headquartered in the San Francisco Bay Area with the subsidiary, ClickHouse B.V., based in Amsterdam, Netherlands.

RethinkDB is a free and open-source, distributed document-oriented database originally created by the company of the same name. The database stores JSON documents with dynamic schemas, and is designed to facilitate pushing real-time updates for query results to applications. Initially seed funded by Y Combinator in June 2009, the company announced in October 2016 that it had been unable to build a sustainable business and its products would be entirely open-sourced without commercial support.

ArangoDB is a graph database system developed by ArangoDB Inc. ArangoDB is a multi-model database system since it supports three data models (graphs, JSON documents, key/value) with one database core and a unified query language AQL (ArangoDB Query Language). AQL is mainly a declarative language and allows the combination of different data access patterns in a single query.

implementation of the Content Repository for Java Technology API (JCR)

declarative graph query language for the Neo4j graph database

open source software

GT.M is a high-throughput key–value database engine optimized for transaction processing. (It is a type also referred to as "schema-less", "schema-free", or "NoSQL".) GT.M is also an application development platform and a compiler for the ISO standard M language, also known as MUMPS.

FoundationDB is a free and open-source multi-model distributed NoSQL database owned by Apple Inc. with a shared-nothing architecture. The product was designed around a "core" database, with additional features supplied in "layers." The core database exposes an ordered key–value store with transactions. The transactions are able to read or write multiple keys stored on any machine in the cluster while fully supporting ACID properties. Transactions are used to implement a variety of data models via layers.

Hypertable was an open-source software project to implement a database management system inspired by publications on the design of Google's Bigtable.

database management system designed to support multiple data models against a single, integrated backend

thumb|300px|LYME (software bundle) is based on Erlang and comprises Mnesia. It is entirely composed of [[free and open-source software]] Mnesia is a distributed, soft real-time database management system written in the Erlang programming language. It is distributed as part of the Open Telecom Platform.