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eXtremeDB/rt Questions and Answers

We hope this answers your questions about eXtremeDB/rt.  If you have any further questions about it, or would like to get a free trial, please contact us.

Q) What is eXtremeDB/rt?

A)  eXtremeDB/rt is the first and only commercial, supported, embedded deterministic database management system. eXtremeDB/rt enforces database transaction deadlines through time-cognizant transaction managers.

Q) Do ACID properties apply to eXtremeDB/rt?

A)  Yes, in addition to supporting time-cognizant transactions, the eXtremeDB/rt transaction manager (or transaction scheduler) fully supports database ACID (atomicity, consistency, isolation, and durability) properties.

Q) What class of applications benefit from using eXtremeDB/rt?

A)  eXtremeDB/rt is designed for mission critical and safety critical hard-real-time applications. Examples include avionics and aircraft navigation systems, driver assistance systems, medical equipment, railway systems, medical systems and energy systems.

Q) What storage media does eXtremeDB/rt support?

A)   At present, eXtremeDB/rt supports in-memory databases. In persistent database systems, the response time of transactions are determined not only by CPU load, but also by I/O latency, which adds to the complexity of real-time database kernel algorithms. That said, supporting databases in persistent secondary storage such as high-capacity flash memories, which is increasingly common in modern embedded systems, is vitally important for real-time systems’ developers. eXtremeDB/rt kernel will soon be extended with algorithms that are “I/O aware” to guarantee transaction response times in the presence of persistent media.

Q) A search of the internet for ‘real-time database’ is dominated by systems that provide real-time analytics. What is the difference between those products and eXtremeDB/rt ?

A)  This is about an approach to getting analytics on data as it is being streamed into the database, as opposed to having to execute queries against the database after the data has been ingested. In this context, the terms “real-time” and “fast” are synonymous (and subjective). In contrast, eXtremeDB/rt is a true real-time DBMS that supports time-cognizant transaction managers on a number of real-time operating systems and hardware platforms. Through the enforcement of transaction deadlines, eXtremeDB/rt is objectively real-time.

Q) What operating systems is eXtremeDB/rt available for?

A)  In order to satisfy hard-real time requirements, the eXtremeDB/rt target applications must run in the context of a real-time operating system or have direct access to hardware resources such as interrupts, and timers. At present, eXtremeDB/rt is available for Azure RTOS ThreadX, Deos™ from DDC-I, embOS® from SEGGER, FreeRTOS™ from Amazon, Green Hills Software INTEGRITY, LynxOS®, QNX, SIEMENS’ Nucleus® and WindRiver’s VxWorks®, all on select hardware. In addition, eXtremeDB/rt functionality can be evaluated in the context of a non-real-time OS — Linux, MacOS, QNX, and Microsoft Windows with the understanding that real-time provisions may be compromised by those non-real-time OS.

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Q) Is eXtremeDB/rt available for the certified versions of the operating systems mentioned above?

A)  Yes, for some. At present, eXtremeDB/rt is available for Deos, LynxOS-178B, VxWorks 653 and INTEGRITY 178B (on select hardware).

Q) How can we evaluate eXtremeDB/rt ?

A)  The nature of eXtremeDB/rt’s tight integration with the RTOS and target hardware requires that each evaluation package be assembled uniquely for your needs. Please contact us so that we can gather information on your RTOS vendor, version, target hardware, tool chain, and so on.

If you would like to get an overview of eXtremeDB/rt outside of an RTOS, “desktop” evaluation packages are available for immediate download for Linux (any Intel® 64 architecture), MacOS and Microsoft Windows (VS2017, any Intel® 64 architecture) platforms. The desktop distributions include numerous samples that demonstrate the eXtremeDB/rt API.

You are also welcome to contact us, and we will send you a download of eXtremeDB/rt running in the FreeRTOS simulator.

Q) How is eXtremeDB/rt licensed ?

A)  As eluded to in the previous answer, eXtremeDB/rt is always licensed with complete source code, and for specific target systems. It is an annual subscription for which the amount is determined by the number and type of target systems and development team size, and includes technical support and software maintenance.

Related Resources

Documentation & Collateral


Review the eXtremeDB/rt data sheet


Learn more about eXtremeDB/rt in our on-line documentation

To Err is Human. The Case for Buy Over Build in Hard Real-time Database Management Systems

In the News

eXtremeDB/rt deterministic DBMS

Tailored to your needs

The nature of eXtremeDB/rt’s tight integration with the RTOS and target hardware requires that each evaluation package be assembled uniquely for your needs.  Please contact us so that we can gather information on your RTOS vendor, version, target hardware, tool chain, and so on.

View the ever-expanding list of supported real-time operating systems.

Send us an email

Give us a call


Desktop distributions

Free desktop evaluation packages of eXtremeDB/rt for Linux, MacOS, QNX and Windows platforms are available for immediate no-hassle download. Learn more about the programming interface and various real-time and non-real-time features of eXtremeDB/rt. After you have tried the desktop version, we hope you’ll contact us for a free trial of eXtremeDB/rt tailored to the needs of your RTOS.

You are also welcome to contact us, and we will send you a download of eXtremeDB/rt running in the FreeRTOS simulator.

News and articles about real-time database management.

COTS Cover photo July 2022

"Soft v Hard Real-time Systems" Embedded Computing, November 4, 2022

Real-time transaction timeline

"Embedded Databases in Real-Time Systems", March 14, 2022

Steve Graves, President and CEO, McObject

"Embedded Executive: Steve Graves, President and CEO, McObject", January, 2022 An interview reviewing key concepts in real-time computing.

COTS article about eXtremeDB/rt

"Databases in Hard Real Time" McObject Launches True Real-Time Deterministic Database for embOS Real-time Operating System Applications,, October 15, 2021

COTS article about eXtremeDB/rt

"Keeping A Mission-Critical Deterministic DBMS On Time" by McObject CTO Andrei Gorine, September 20, 2021

COTS article about eXtremeDB/rt

"Real time tasks need real time data" Read the Wind River blog, September 7, 2021

We're grateful for the partnerships we have with industry leaders, and invite you to read what they say about eXtremeDB/rt in our joint press releases.

Azure RTOS ThreadX

“Managing data with a hard real-time requirement is a challenge for developers,” comments Tony Shakib, Partner General Manager, Microsoft Azure IoT. “Developers have had to use current solutions that may not meet time constraints or write their own database system. eXtremeDB/rt brings a solution to Microsoft Azure developers that eliminates this trade off.”

Read the joint press release.

DDC-I’s Deos

eXtremeDB/rt provides an excellent option for developers of resource-constrained, mission-critical embedded systems who require a compact, real-time embedded database,” said Greg Rose, vice president of marketing and product management at DDC-I. “We look forward to working with McObject to offer eXtremeDB/rt to embedded developers utilizing our Deos real-time operating system.”

Read the joint press release.

embOS from SEGGER

SEGGER’s CEO, Ivo Geilenbruegge, had this to say: “We are excited that McObject has created a first-of-its-kind real-time database system to complement our embOS RTOS and extend support for hard real-time systems to include database operations. Real-time systems are following the trend of embedded systems in that they are being called upon to manage more (and more complex) data."

Read the joint press release.


Richard Barry, FreeRTOS founder, said “It is good to have another high-quality option for FreeRTOS users, this time providing a real-time deterministic database which can, as just one example, fulfill a crucial role in the Industrial Internet of Things (IIoT): data collection, aggregation, and distribution in oil rig blow-out prevention (BOP) systems. A BOP is a specialized device equipped with sensors to detect a “kick” and actuate valves to prevent a catastrophic blowout.” Richard continued, “The need to detect and respond within deadlines is emblematic of real-time industrial systems.”

Read the press release.

INTEGRITY from Green Hills Software

Joe Fabbre, Global Technology Director for Green Hills had this to say: “McObject has created a unique real-time database that complements our INTEGRITY RTOS and extends hard real-time support to database operations. Advanced applications in real-time systems are being called upon to manage more (and more complex) data. eXtremeDB/rt gives developers of these systems an off the shelf solution for real-time data management.”

Read the joint press release.


“We were delighted to work with McObject to bring eXtremeDB/rt to the LynxOS partner ecosystem. Our companies share the vision that real-time systems are becoming more sophisticated and consequently have to manage more complex data. eXtremeDB/rt fills a critical gap in the technology stack,” said Pavan Singh, VP of product management, Lynx Software Technologies.

Read the joint press release.

QNX Neutrino RTOS

“Real-time performance can benefit embedded software developers in many market segments including autonomous systems, industrial control, robotics and medical devices,” said Romain Saha, Strategic Alliances Director at BlackBerry QNX: “McObject builds upon many years of QNX support by bringing eXtremeDB/rt to the latest version of the QNX Software Development Platform.”

Read the joint press release.


“McObject’s eXtremeDB/rt allows Nucleus customers to have a truly embedded database solution that allows them to meet the determinism they require in a commercial-off-the-shelf solution.” said Jeff Hancock, Siemens Embedded Senior Product Manager. “eXtremeDB/rt helps Nucleus customers manage ever-growing data requirements.”

Read the joint press release.

WindRiver VxWorks

“Through our work with McObject, we’re helping customers modernize and accelerate the delivery of reliable intelligent systems that demand real-time requirements,” said Michel Chabroux, Senior Director, Product Management, Wind River. “We look forward to building on our proven track record of success with McObject to help advance the next generation of cloud-connected intelligent systems with increasingly challenging edge compute needs.”

Read the joint press release.