Reliable In-memory Database System

Proven the fastest and most reliable in-memory or hybrid database system from edge to cloud.


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eXtremeDB was designed specifically as an in-memory database system, not an afterthought.

The eXtremeDB database management system was originally designed and optimized to be an in-memory database system (IMDS), with direct data manipulation.  When a database management system is created, it will, by design and implementation, be either an in-memory database system or an on-disk database management system. This initial choice affects the fundamental optimization strategies that will be baked into the database system code.  (For a more in-depth explanation, please review the McObject white paper, Will The Real In-memory Database Please Stand Up on this specific topic.)  eXtremeDB is the reliable in-memory database system found around the world in systems from military helicopters to nuclear power plants that cannot afford to fail. 


The in-memory database designed specifically for embedded systems.


Real vs. imitation in-memory database systems – what’s the difference and why does it matter?

Operator Interface for the transportation subsystem, Radioactive Waste Treatment Facility, Smolensk Nuclear Power Plant. Real-time data populating the BISMARC interface is drawn from the eXtremeDB in-memory database.

The eXtremeDB reliable in-memory database system is found in systems that cannot afford to fail

In-memory database performance

To optimize an on-disk database is to minimize disk I/O, so its design will use extra CPU cycles and extra memory to reduce or eliminate I/O.  Conversely, IMDSs by definition eliminate all disk I/O.  In other words, their optimization is primarily about delivering the highest performance at a given level of processing power.  For an in-memory database, the focus is on reducing demand for CPU cycles. Because memory is storage for an IMDS, reducing memory overhead (i.e. RAM consumed for anything other than storing data) is also a key objective.

Using eXtremeDB on embedded platforms (e.g. ARM, PowerPC), typical read and write accesses are at the level of a few microseconds, or less. When used on workstation or server platforms, performance is sub-microsecond.  (Visit this page to read one of our in-memory benchmarks.)

When eXtremeDB is used as an embedded database system, the engine is reentrant, allowing for concurrent access by multiple execution tasks or threads. Used on multi-tasking platforms (e.g. Linux and VxWorks RTP), databases can be created in shared memory for concurrent access among many processes.  eXtremeDB transactions support the ACID properties, assuring data integrity.

eXtremeDB can also operate as a client/server database system. Client applications can be local (executing on the same system as the eXtremeDB server) or remote (executing on different systems that are connected to the eXtremeDB server system via TCP/IP).



Learn how eXtremeDB reduces memory consumption.


Learn more about the advantages and disadvantages of embedded database systems and client/server database systems.


We created the eXtremeDB in-memory database for professional developers, and offer more features to chose from than any other DBMS.  


Read more about in-memory database performance. Review a summary of the white paper, Gaining an Extreme Performance Advantage.  McObject examined on-disk database system performance vs. that of an IMDS operating with transaction logging. To highlight the effects on performance of today’s diverse data storage options, we ran separate tests using hard disk drive (HDD), solid state drive (SSD) and state-of-the-art flash-based devices as storage for on-disk database records, and for the IMDS transaction log.

Hybrid data storage

Unlike other IMDS, eXtremeDB can combine the strengths of on-disk and in-memory database systems. In other words, eXtremeDB databases can be all-in-memory, all-persistent, or have a mix of in-memory tables and persistent tables. This unparalleled flexibility enables developers to tailor data management in order to optimize applications for speed and persistence.  System developers can make intelligent trade-offs between performance, cost-efficiency, power consumption, and physical space-conserving data storage hardware.


Learn why being designed and implemented as an in-memory database system is a crucial first step for a hybrid database system.


Learn about eXtremeDB hybrid data management.


Get technical about eXtremeDB hybrid data management in our online documentation.

Chart of the hybrid storage of the eXtremeDB in-memory database system

A scalable in-memory database

An eXtremeDB database can be horizontally partitioned (“sharded”) for scalability. This feature leverages the processing power of multiple servers and/or multiple CPUs and/or multiple cores by distributing the data and the data processing to multiple instances of the eXtremeDB server. eXtremeDB’s distributed query engine isolates client applications from the details of the topology. When this technique is applied to multiple servers, the single-server limitation on the size of an in-memory database is overcome. In other words, if a single server has a maximum memory capacity of 768GB, then five servers have an aggregate capacity of 3.84TB.

eXtremeDB offers different distributed database options to address different objectives. This table summarizes the primary purpose and characteristics of each distributed database option (some of which may be combined, e.g. Sharding, Cluster and High Availability).  Learn more about distributed data management with eXtremeDB.

eXtremeDB is a scalable IMDS

Distributed database options

eXtremeDB offers different distributed database options to address different objectives. Review this table to learn more. 

Elastic scalability

Learn more about Sharding.

Created to be a flexible tool for the professional developer

Fast, flexible eXtremeDB offers more features than any other database management system on the market.


High Availability

Designed to power systems that cannot afford to fail, eXtremeDB-HA delivers the highest degree of availability, along with its unsurpassed performance and exceptionally small footprint.


eXtremeDB Cluster is unique as the first clustering database system to offer an embedded architecture.

Native and SQL APIs for C/C++, Java, C#, Python

eXtremeDB provides the developer with multiple application programming interfaces (APIs). Learn more 

A Wide Range of Supported Data Types

eXtremeDB supports structures, arrays, vectors and BLOBs for maximum efficiency. Learn more about this and other key features.

Multiple Database Indexes

B-Tree, R-Tree, Patricia Trie, KD-Tree, Trigram and Hash indexes.  Learn more


Security and Reliability

eXtremeDB protects your database with encryption, and CRC32 to detect tampering.

Used by innovative industry leaders in over 30,000,000 deployments world-wide in these markets and others.

Telecom & Netcom

eXtremeDB powers routers, application traffic management, SCADA network fault management and more from industry leaders like F5, ViaSat, Motorola, Sandvine, Hutchinson, TNS and Ribbon that require real-time performance and five 9s high availability.

Internet of Things

eXtremeDB’s Active Replication Fabric™ manages all aspects of IoT data communication: security, low bandwidth, intermittent connections, multi-tier and bi-directional replication, and more.

Aerospace & Defense

Northrop Grumman, Lockheed Martin, British Aerospace, EADS and others depend on eXtremeDB’s reliability, unmatched performance and broad platform support.

Financial Systems

eXtremeDB’s unique hybrid row- and columnar-layout (OLTP and time series) coupled with pipelined functions for statistical analysis and scalable distributed database architecture power record-setting STAC-M3 benchmark results.

Consumer Electronics

JVC, DirecTV, GoPro and others all discovered that eXtremeDB’s small code size, portable data format and efficient use of compute & storage can reduce component cost while also supporting data-hungry new features.

Industrial Control

eXtremeDB’s sophisticated event notification systems, time series data processing and high availability have powered its wide-spread adoption in SCADA, fleet management, smart building automation and other verticals.

Related Resources

White papers about in-memory database performance and more

White Papers for Professional Developers about In-memory Database Systems

We have been testing, improving on, and retesting our software from the beginning in 2001 in order to provide our clients with the best possible data management solutions. Read “Database Persistence, Without The Performance Penalty” and more.  

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On demand Webinars about IMDS performance and more

Webinars for Professional Developers

Watch to on-demand Webinars, hosted by experts, about proven database management system practices.  Watch What Makes a Database System ‘In-Memory’?.  Or, Data Acceleration and Business Continuity with McObject’s eXtremeDB Cache and others.

Review our list of Webinars

in-memory DBMS for professional developers

IoT Vendor of the Year 2018

eXtremeDB is the in-memory DBMS for professional developers

Best Development Tool & Operating System at IoT World


eXtremeDB FAQs

List of eXtremeDB features


eXtremeDB documentation

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