# List of in-memory databases

Notable in-memory database system software includes:
| Name | Developer | Availability | Client Interface | License | Description/Notes |
| Aerospike DBS | Aerospike Company | 2012 | Java, C#, C, Python, Go, Node.js, Perl, libevent, PHP, Ruby, Rust | Open Source (AGPL) | Flash-optimized in-memory open source NoSQL database. |
| ALTIBASE HDB | Altibase Corporation | 1999 | Java, C, C++, JDBC, ODBC, SQL | Proprietary | Altibase is a hybrid DBMS that combines an in-memory database with a conventional disk-resident database in a single unified engine. It supports full ACID properties and standard connectivity interfaces such as JDBC and ODBC, as well as interoperability. Altibase Corporation has recently made the decision to discontinue the Altibase 7.1 open source edition, effective March 17, 2023, on its Github page (https://github.com/Altibase/altibase). |
| ALTIBASE XDB | Altibase Corporation | 1999 | Java, C, C++, JDBC, ODBC, SQL | Proprietary | General purpose database that has high data processing speeds in main-memory alone. It comes with high-availability, replication and scalability features; three interfaces (including Direct Access Mode and Direct Access API Mode) as well as conventional client/server protocols such as TCP/IP and IPC for more complex database operations. Supports full ACID properties, standard connectivity interfaces such as JDBC and ODBC [fully supported] as well as interoperability. |
| Apache Ignite | Apache Software Foundation, GridGain Systems | 2014 | Java, SQL, JDBC, ODBC | Open Source (Apache License Version 2.0) | Apache Ignite is an in-memory computing platform that is durable, strongly consistent, and highly available with powerful SQL, key-value and processing APIs. With full SQL support, one of the main use cases for Apache Ignite is the in-memory database which scales horizontally and provides ACID transactions. |
| ArangoDB | ArangoDB GmbH | 2011 | AQL, HTTP, Java, JavaScript, PHP, Go, Scala, .Net, Python, Ruby | Business Source License 1.1 | ArangoDB is a transactional native multi-model database supporting two major NoSQL data models (graph and document) with one query language. Written in C++ and optimized for in-memory computing. In addition ArangoDB integrated RocksDB for persistent storage. ArangoDB supports Java, JavaScript, Python, PHP, NodeJS, C++ and Elixir. For resilient cluster behavior, ArangoDB offers a Raft-based cluster management. |
| Datablitz (formerly Dali) | Bell Labs (Alcatel-Lucent) | 1997 | | Proprietary | Dali prototype was a research project at Bell Labs. It was commercialized and used by Lucent as database for in premier wireline and wireless products. |
| DuckDB | DuckDB Labs | 2019 | C/C++, Python, R, Java, Go, Rust, Node.js, Wasm, ODBC, ADBC, and more | Open source (MIT License) | DuckDB is an in-process database system designed for high performance for analytical query workloads offers client APIs for a wide range of languages. |
| Exasol | Exasol AG | 2000 | JDBC, ODBC, ADO.NET, Python, SQL, R, Go, Rest API | Proprietary | Exasol is in-memory, column-oriented analytical relational database management system which is developed by Exasol AG. |
| Ehcache | Terracotta, Inc. (Software AG) | 2006 | Java | Open source (Apache License) | For Java, distributed |
| eXtremeDB | McObject | 2001 | SQL, Lua, C, C++, C#, Java, Python | Proprietary | Cross-platform, including Linux, Windows, RTOS and server platforms. Interfaces include type-safe, native C/C++; native Java & .NET; SQL/ODBC/JDBC. Specialized editions for (for example) clustering, high availability, 64-bit support, and hybrid (in-memory and persistent) storage. eXtremeDB Financial Edition implements columnar data handling, vector-based statistical function library, integrated performance monitoring. |
| H2 (DBMS) | H2 | | Java, ODBC, JDBC | Open Source (Mozilla Public License or Eclipse Public License) | For Java |
| HSQLDB | HSQL Development Group | 2001 | Java, SQL, ODBC | Open Source (BSD License) | Relational, for Java |
| Hazelcast | Hazelcast Team | | Java, C#, C++, Node.js, Python, Go | Open Source (Apache License 2.0) | Hazelcast is an in-memory computing platform that runs applications with extremely high throughput and low latency requirements. It offers speed, scale, simplicity, resiliency, and security in a distributed architecture. It consists of an in-memory data grid and a distributed stream processing engine that work together to run many types of data processing workloads. |
| Informix Warehouse Accelerator | IBM | | JDBC, SQL | Proprietary | IWA supports Dynamic In-memory (in-memory columnar processing) Parallel Vector Processing, Actionable Compression, and Data Skipping technologies, collectively called "Blink Technology" by IBM (the same technology underlying IBM BLU Acceleration). The Informix Advanced Enterprise and Advanced Workgroup Editions include IWA. Released: March 2011. |
| IBM Db2 | IBM | 1991 | ODBC, JDBC, C, C++, Python | Proprietary | IBM BLU Acceleration |
| InfinityDB | Boiler Bay Inc. | 2002 | Java, HTTP, | Proprietary | Java extended standard ConcurrentNavigableMap NoSQL with caching, durability, transactions, compression. |
| Infinispan | Infinispan team, Sponsored by Red Hat. | 2009 | Java, .Net, REST, RESP Protocol, Memcached | Open Source (Apache License 2.0) | Infinispan is a distributed in-memory database offering caching, persistence, transactions, querying, Redis and Memcached compatible, and cloud-native scalability (cross-site replication). |
| Kinetica | Kinetica (formerly GIS Federal) | 2014 | C++, C#, Java, JavaScript, Node.js. Python, HTTP | Proprietary | GPU-accelerated, in-memory, distributed database for analytics. Functions like a RDBMS (structured data) for fast analytics on datasets in the hundreds of GBs to tens of TBs range. Interact with SQL and REST API. Geospatial objects and functions. UDF framework allows for custom code and machine learning workloads to run in-database. Received $50mil Series A funding in June 2017. |
| Memcached | Danga Interactive | 2003 | Proprietary text and binary protocols in any language | Open Source (BSD) | Hashtable with LRU purge |
| SingleStore (formerly MemSQL) | SingleStore, Inc. | | | Proprietary | SQL relational |
| Microsoft COM+ IMDB | Microsoft Corporation | | | Proprietary | Defunct |
| Microsoft SQL Server | Microsoft | 2012 | | Proprietary | In SQL Server 2014, a feature codenamed Hekaton, and named In Memory OLTP, provided limited memory optimization, which can be used in conjunction with natively compile stored procedures which are persisted as C. In SQL Server 2012, an in-memory technology called xVelocity column-store indexes targeted for data-warehouse workloads. |
| Mimer SQL | Mimer Information Technology | | SQL, ODBC, JDBC, ADO.NET, Embedded SQL, C, C++, Python | Proprietary | Mimer SQL is a general purpose relational database server that can be configured to run fully in-memory. Mimer SQL has full ACID support, support for stored procedures and is the only database that has a full score on SQL compliance |
| Mnesia | Ericsson | 2014 | | Open Source Erlang License | 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. |
| MonetDB | MonetDB Solutions, CWI | 2004 | SQL, ODBC, JDBC, C, C++, Java, Python, PHP, Node.js, Perl, Ruby, R, MAL | open-source MonetDB License, based on MPL 2.0 as of version Jul2015. | in-memory optimized column-oriented relational database management system (RDBMS) written in C with an SQL top-level interface and ODBC, JDBC drivers |
| MySQL NDB Cluster | MySQL | 1997 | | Dual license open source(GNU-GPLv2) and optional proprietary | Highly available distributed real-time in-memory NoSQL database. Often used with MySQL for SQL cross-shard parallel query processing. |
| OmniSci | OmniSci (formerly MapD) | 2013 | | Open Source (Apache License 2.0) | GPU-accelerated, SQL database and visualization platform for real-time analytics. Product consists of the core database plus a BI visualization tool. Received $55mil Series C funding in Aug 2018. v4.8 announced in August 2019 with support for JupyterLab. |
| Oracle RDBMS | Oracle Corporation | 2014 | | Proprietary | RDBMS Oracle 12c contains an option for in-memory technology (additional licenses required). |
| Oracle Coherence | Oracle Corporation | | | Proprietary with developer download | For Java, relational, distributed |
| Perst | McObject | 2006 | Java, Android, .NET | [Dual_license] open source(GNU-GPLv3) and optional proprietary | Object-oriented embedded database system for Java, Android and .NET platforms. No ORM. Schema evolution, XML export/import, replication, specialized indexes, including full text, b-tree, t-tree, r-tree, patricia trie, kd-tree and time series |
| Polyhedra | ENEA AB (previously Perihelion Software) | 1993 | | Proprietary, with a free-to-use edition (Polyhedra Lite) | Relational (SQL, ODBC, JDBC) in-memory database system originally developed for use in SCADA and embedded systems, but used in a variety of other applications including financial systems. Supports data durability via snapshots and journal logging, and high availability via a hot-standby. First released in 1993; version 8.7 released in March 2013. Polyhedra Lite appeared with a free-to-use license in 2012. |
| Redis | Redis Labs | 2009 | C, C++, Python, Lua, C#, etc. | Redis Source Available License v2 (RSALv2) and the Server Side Public License v1 (SSPLv1) | Redis is a source-available software project that implements data structure servers. It is networked, in-memory, and stores keys with optional durability. |
| SafePeak | SafePeak Technologies | | | Proprietary | Automated In-Memory Dynamic Caching for SQL Server OLTP applications and databases. Code-free, Dynamic Caching, Relational |
| SAP HANA | SAP SE | 2012 | | Proprietary | SAP HANA, short for 'High Performance Analytic Appliance' is an in-memory, column-oriented, relational database management system written in C, C++ |
| solidDB | Unicom Global | 1992 | | Proprietary | Relational with standard SQL support. ODBC and JDBC interfaces. Includes in-memory and on-disk tables in the same engine. Supports high availability. |
| SQL CE | Microsoft Corporation | | | Free | Compact relational embedded database produced by Microsoft for applications that run on mobile devices and desktops. ADO.NET, OLE DB. No ODBC driver. |
| SQLite | SQLite | | | Open Source (Public domain) | SQL database that supports in-memory storage with the :memory: connection string. |
| Tarantool | Mail.ru Group | 2010 | | Open Source (BSD) | In-memory database and application server (data grid) |
| TerminusDB | TerminusDB (formerly DataChemist) | 2019 | JavaScript, Python, Prolog, Rust, JSON-LD | Open Source (Apache 2.0) | Open source in-memory graph database designed for knowledge graph representation |
| TimesTen | now Oracle Corporation | 1997 | Java, JDBC, ODBC, SQL, PLSQL, C | Proprietary | Standalone database or in-memory cache for Oracle Database |
| TPF (Transaction Processing Facility) | IBM | 1979 | | Marketed | Generalized extension of IBM Airlines reservation system. IBM's DB/DC system backed up the in-memory transaction processing computer. |
| Starcounter | Starcounter AB | 2014 | | Proprietary | In-memory database engine combined with an application server that melds the Virtual Machine and the Database Management System. |
| VoltDB | VoltDB Inc. | | | Open Source (GPL) / Proprietary | Relational; implements H-Store design |
| Xeround | Xeround Inc. | | | Proprietary / Not for sale, service only | Cloud database, defunct as of 2014 |
| CursusDB | CursusDB | 2023 | JAVA, GO, C#, Python, Node.JS | Open Source (GPL) | CursusDB is an in-memory document-oriented, real-time capable database management system that is open-source licensed under GPL. |