EXtremeDB

Infobox_Software
name = "e"X"treme"DB

caption =
developer = McObject
latest_release_version = 3.1
latest_release_date = April 2, 2008
operating_system = Cross-platform
genre = DBMS
license = Commercial license
website = http://www.mcobject.com

"e"X"treme"DB is an ACID-compliant embedded database management system (DBMS) designed for embedded systems and applications with real-time performance requirements. "e"X"treme"DB is an in-memory database (also known as a main memory database, or MMDB), a type of database system that eliminates disk access by storing data in main memory and sending changes to the system’s hard disk (if there is one) only when specified by the application. In contrast, traditional ‘on-disk’ DBMSs, which comprise the great majority of database systems, cache frequently requested data in memory for faster access, but automatically write data updates, insertions, and deletes through to the hard disk.

Uses

"e"X"treme"DB is integrated within the embedded software in hardware devices including consumer electronics (such as set-top boxes, MP3 players and mobile phone handsets); network routers, load balancing, and security appliances; telecommunications/networking (including switches, routers, BSS/OSS, session border controllers, WiMAX base stations, test equipment and many other applications); on-board automotive systems including vehicle telematics; military and aerospace applications; and industrial automation. "e"X"treme"DB is also used in non-embedded applications that are inherently real-time, such as securities trading systems.

Product features

In-memory data storage

"e"X"treme"DB provides direct access to data, which is stored entirely in memory. This eliminates disk reads and writes from the data management process, and removes the need for complex software logic such as database caching functions. With this simplified design, "e"X"treme"DB provides a code “footprint” as small as 50K, and typical database read and write accesses at the level of a few microseconds, or less.

Transactions

For data integrity, "e"X"treme"DB transactions support the ACID properties, ensuring that operations grouped into transactions will complete together or the database will be rolled back to a pre-transaction state.

APIs

Native API

"e"X"treme"DB's native application programming interface (API) includes a standard function library for basic database operations, as well as data manipulation functions that are generated when the database scheme is compiled, and which derives from the application’s data model. Database functions therefore reflect the purpose and schema for which the database is being used. The native API is type-safe – the developer's C/C++ compiler will catch data typing and assignment errors when the application is built.

QL

"e"X"treme"DB offers a SQL API, called "e"X"treme"SQL, which implements much of the ANSI SQL-89 specification. "e"X"treme"SQL includes "e"X"treme"DB-specific extensions including support for structures, arrays and vectors, as well as query optimizations based on specific "e"X"treme"DB capabilities.

XML

"e"X"treme"DB provides XML Extensions to facilitate simple schema evolution and the exchange of data between the "e"X"treme"DB embedded database and external systems.

Developer tools

Typical "e"X"treme"DB users are software developers creating applications in the C and C++ languages, who embed "e"X"treme"DB’s data management functions in their application code, with the goal of maximum run-time efficiency. "e"X"treme"DB features for coding in these languages include:

* Support for virtually all data types, including structures, arrays, vectors and binary large objects (BLOBs)

* Querying methods include hash indexes for exact match searches

* Tree indexes that support queries for pattern match, range retrieval and sorting

* “Voluntary” indexes for program control over index population

* Object identifier references provide direct data access

* Autoid for system-defined object identifiers

* Indexes that contain only a reference to data, rather than storing duplicate data, in order to minimize memory requirements

* Synchronous/asynchronous event notifications

* Object history

High Availability

For software applications that require high availability, "e"X"treme"DB High Availability (HA) Edition is designed to ensure that changes to a master database and identical standby databases succeed or fail together, and enables deployment of multiple fully synchronized "e"X"treme"DB-HA databases within the same hardware device or across multiple, widely distributed systems. A predictable response time is created via the HA protocol's “time cognizance” – if a master or replica database fails to respond within a pre-set limit, it is automatically decommissioned and replaced in its role by a responding "e"X"treme"DB-HA database instance.

Transaction Logging

The "e"X"treme"DB Transaction Logging Edition provides additional recovery capabilities. When transaction logging is active and enabled, all updates to data objects are logged to a set of files on disk, or on a network device. If the memory content is damaged or destroyed, the exact state of the database is restored by an automatic roll forward procedure.

64-Bit Database

"e"X"treme"DB-64 increases maximum database size by adding support for 64-bit micro-processors and operating systems. Compared to traditional 32-bit processors, 64-bit technology approximately doubles the amount of data a CPU can handle per clock cycle, and increases the amount of memory a system can address from approximately 3GB to more than one terabyte (1000GB).

Hybrid Storage ("e"X"treme"DB Fusion)

"e"X"treme"DB Fusion is marketed by McObject as a "hybrid" embedded database system, in that it provides both in-memory and on-disk data storage in a single database instance. A notation in the database schema causes specified records to be managed entirely in main memory, while others are saved to disk. "e"X"treme"DB Fusion's on-disk data management process uses database caching to keep frequently requested records in memory (while flushing updates through to permanent storage), while records specified as in-memory are accessed directly, eliminating mechanical disk I/O, multiple data copies, and (now redundant) caching processes.

Benefits of this hybrid approach cited by McObject include performance gains when sorting, storing and retrieving specified data entirely in memory, rather than going to disk; cost, because a less expensive hard disk can be substituted for more expensive RAM as a data storage medium; persistence; and form factor, because RAM chips can’t yet approach the density of an 80GB micro-drive.

Kernel Mode ("e"X"treme"DB Kernel Mode)

In 2008, McObject released "e"X"treme"DB Kernel Mode (KM), an embedded database system designed for deployment in the operating system kernel. The company described "e"X"treme"DB-KM's intended use as providing local data management for application logic that is deployed in kernel mode, in order to eliminating the context switches (and their performance penalty) that occur when a kernel mode process interacts with user mode software (in this case, a database system running in user mode). In a Dr. Dobb's Journal feature [http://www.ddj.com/database/207401567 article] about the new database technology, McObject CTO Andrei Gorine named security applications (such as access control systems and firewalls) and operating-system monitors as applications that commonly place functions in the operating-system kernel and would benefit from a kernel mode database.

upported Platforms

"e"X"treme"DB is highly portable and source code is available. "e"X"treme"DB can also run in the absence of an operating system. Platforms supported by McObject include:
* VxWorks
* QNX Neutrino RTOS
* Linux and Real-Time Linux distributions (MontaVista, Wind River Systems, BlueCat, etc.)
* LynxOS
* Nucleus
* INTEGRITY
* Microsoft Windows Embedded
* eCos
* RTXC Quadros RTOS
* RTX Real-Time Extension for Windows
* HP-UX
* Sun Solaris
* Bare bones boards (no operating system required)

"e"X"treme"DB-based Applications

SOMA Networks - FlexMAX™ Mobile WiMAX System base station

DIRECTV - Electronic programming guide for set-top boxes

JVC - Alneo line of digital audio players

Dalian Commodity Exchange - real-time commodities trading platform

F5 Networks -- BIG-IP Internet traffic optimization devices

Hydril - blowout prevention system for oil and gas drilling

Spirent Communications - TestCenter testing system for communication networks, devices and applications

Siemens – Mobile phone handset

NextPoint Networks - session border controller

Tyco Thermal Controls - DigiTrace heat tracing and control system

Academy of Electrical Power (China) - phasor measurement unit

Articles

Graves, Steve. [http://www.iapplianceweb.com/story/OEG20020104S0070.htm Examining Main Memory Databases] , "iApplianceWeb", January, 2002

Gorine, Andrei. [http://www.eetimes.com/in_focus/communications/OEG20021127S0035 Programming guide manages networked digital TV] , "EE Times", December 2, 2002

Gorine, Andrei. [http://www.mcobject.com/esesept.shtml Embedded Database Design for High Availability] , "Embedded Systems Europe", September, 2003

Gorine, Andrei. [http://www.mcobject.com/boards_solutions.shtml Building durability into data management for real-time systems] , "Boards & Solutions", September, 2004

Graves, Steve. [http://www.mcobject.com/downloadfiles/ese200501.pdf Developing Effective, Reliable Aerospace Equipment: The Data Management Challenge] , "Embedded Systems Engineering", February, 2005

Gorine, Andrei and Knizhnik, Konstantin. [http://devnet.developerpipeline.com/documents/s=9849/q=1/ddj0512m/0512m.html Memory Management & Embedded Databases] , "Dr. Dobb’s Journal", December, 2005

Graves, Steve. [http://www.esemagazine.com/index.php?option=com_content&task=view&id=85&Itemid=2 MP3 Players: the Music Database Gets Database Software] , "Embedded Systems Engineering", February 2006

Milne, Eric. [http://www.controleng.com/article/CA6547158.html Keeping A Lid On Blowouts] , "Control Engineering", April, 2008

Gorine, Andrei and Krivolapov, Alexander. [http://www.ddj.com/database/207401567 Kernel Mode Databases] , "Dr. Dobb's Journal", May, 2008

Knizhnik, Konstantin. [http://www.ddj.com/architect/208800854 Patricia Tries: A Better Index For Prefix Searches] , "Dr. Dobb's Journal", June, 2008

Graves, Steve. [http://www.embedded.com/columns/technicalinsights/209601833?_requestid=12441 Hybrid Data Management Gets Traction In Set-Top Boxes] , "Embedded.com", July, 2008

External links

* [http://www.mcobject.com/extremedbfamily.shtml "e"X"tremeDB" product family page]