Db2 (Formerly Db2 for LUW)
|Written in||C, C++, assembly, Java|
|Operating system||Linux, Unix-like, Windows|
|Platform||x86-64, x86, Sparc, IBM POWER microprocessors, IA-32|
|Available in||English, Spanish, French, German, Russian, Japanese|
|License||Proprietary commercial software, Proprietary EULA|
Db2 for Linux, UNIX and Windows is a database server product developed by IBM. Sometimes called Db2 LUW for brevity, it is part of the Db2 family of database products. Db2 LUW is the "Common Server" product member of the Db2 family, designed to run on most popular operating systems. By contrast, all other Db2 products are specific to a single platform.
Db2 LUW was initially called Db2 Universal Database (UDB), but over time IBM marketing started to use the same term for other database products, notably mainframe (z-Series) Db2. Thus the Db2 for Linux, UNIX and Windows moniker became necessary to distinguish the common server Db2 LUW product from single-platform Db2 products.
The current Db2 LUW product runs on multiple Linux and UNIX distributions, such as Red Hat Enterprise Linux, SUSE Linux, IBM AIX, HP-UX, and Solaris, and most Windows systems. Earlier versions also ran on OS/2. Multiple editions are marketed for different sizes of organisation and uses. The same code base is also marketed without the Db2 name as IBM InfoSphere Warehouse edition.
In 2017, the "Db2 UDB" name became just "Db2".
The first release of Advanced Db2 LUW was as Db2 Universal Database version 5, available on UNIX, Windows and OS/2 platforms. This new product stemmed from two earlier products, Db2 Common Server version 2 and Db2 Parallel Edition. Db2 Universal Database version 5 continued IBM's new direction of using a common code base to support Db2 on different platforms, while incorporating the shared nothing features of Db2 Parallel Edition to support large data warehousing databases.
In addition to standard ACID-compliant row-organized relational database functionality, some of its key features are:
- IBM BLU Acceleration: OLAP oriented column-organized tables, compressed with order-preserving "approximate Huffman encoding", exploiting SIMD vector processing of compressed data. Because the compression is order preserving, a greater range of operations can be performed on compressed data.
- pureScale: A data-sharing clustering of the database over multiple servers for scalability and resilience. This technology was taken from the mainframe (z-Series) Db2 product. This form of clustering suits OLTP workloads well.
- Database partitioning feature: A shared-nothing approach to clustering, with data hashed across multiple partitions on the same server or different processors. With the right database design, this approach allows near-linear scaling. This form of clustering is generally employed for large data warehouses rather than OLTP workloads.
- XML support: XML-specific storage and indexing, accessible by both SQL and also XQuery.
- NoSQL support: Currently graph triple stores and JSON support
IBM DB2 Express-C
DB2 Express-C (11.1) / June 15, 2016
|Written in||C, C++|
|Website||DB2 Express-C homepage at ibm.com|
IBM DB2 Express-C is a free to download, use and redistribute edition of the IBM DB2 data server, which has both XML database and relational database management system features. It is limited to two CPU cores, 16 GB of RAM, a database size of 15 TB, and no Enterprise support and fix packs. DB2 Express-C has no limit on number of users.
On January 30, 2006, IBM announced a special free version of DB2 Express edition called DB2 Express-C. The DB2 Express-C edition was created for the 8.2 release of IBM DB2. After this DB2 Express-C was created for all new DB2 versions: 9.1 (codenamed "Viper"), 9.5 (codename "Viper 2"), 9.7 (codename "Cobra"), 10.01 (codename "Galileo"), 10.5 (codename "Kepler") and 11.1.
IBM DB2 Express C supports 32- and 64-bit x86 Windows XP, Vista and Windows 7, (with some issues in Windows 7). Linux version runs on 32- and 64-bit Intel/AMD and 64-bit IBM POWER. Solaris and Mac OS X versions are supported on x64 AMD/Intel machines only. List of supported Linux distributions: Ubuntu 8.04.1 LTS, RHEL 5, SLES 10 and 11, openSUSE 12.3. Other distributions are reported to work too and released .deb packages for Ubuntu works also on Debian.
IBM DB2 Express-C prior to version 10.5 did not limit the amount of data that can be stored in a database; as of version 10.5, there is a 15 TB limit. The database engine does not limit the number of concurrent user connections. IBM offers 64-bit native versions of DB2 Express-C for all supported platforms, but 32-bit versions are still available for some environments. Remote applications can connect to DB2 Express-C over TCP/IP V4, TCP/IP V6, or named pipes. The DB2 Express-C database engine is limited to use up to 16 GB RAM (increase from 4 GB with v10.5) and two CPU cores, but it can be installed and used on machines of any size, with the remaining memory and CPU available for use by the O/S and other applications.
The DB2 Express-C feature set is very similar to DB2 Express edition (a paid product), but the main difference is that Express-C has lower CPU and memory limits. It has the following extra features enabled:
- Backup compression
- Homogeneous federation – only DB2, Informix Data Server and Oracle targets are supported
- Homogeneous SQL replication
- Net Search Extender
- XML storage
- Spatial extender
The following extra features are not supported: Advanced Copy Services, row compression, connection concentrator, DBF partitioning, DB2 governor, PureScale data sharing, geodetic extender, HADR, Homogeneous Q replication, Sybase compatibility, Label Based Access Control, Row and Column Access Control (RCAC), MQT's, MDC, online reorg, query parallelism, query patroller, table partitioning and workload management.
DB2 Express-C is not permitted for use in high availability environments such as involving replication, active-passive, or shared disk clustering. In-place updates of the DB2 software (via patch sets called fix packs) are not available for DB2 Express-C; the existing DB2 Express-C engine must be removed and replaced with a newer release of DB2 Express-C. In either scenario, the DB2 database(s) remain intact on the server and are not touched by the software installation utility. IBM only offers the current version of Express-C on their website, but users may choose to install and run older releases of DB2 Express-C that they have previously downloaded from IBM.
DB2 Express-C version is unsupported and regular DB2 fix packs can not be applied to it. IBM does not release any fixes, but they do publish updated installation images and remove old ones. Unix versions need to be reinstalled, but it is possible to perform in-place updates on Windows versions by just running the installation program of a newer version. If you need access to regular DB2 fix packs, which are released several times per year, you need to buy DB2 Express Edition (or better).
Installation images are traditionally refreshed once for every major DB2 release to sync code with second fix pack. For example, DB2 Express-C for 9.1 release is available as DB2 Express-C 9.1 and DB2 Express-C 9.1.2. DB2 9.7 Express-C was refreshed to 9.7.1 breaking that tradition. DB2 Express-C v10.01 was made available on April 30, 2012.
In DB2 9.7 there are no more annual subscriptions for DB2 Express-C product. Subscription features were moved to the DB2 Express (non "-C") product instead with price tag unchanged. For upgrading DB2 Express-C to DB2 Express you need to reinstall DB2. Uninstalling DB2 does not delete your data or database (which can be recatalogued after a new version of DB2 is installed).
Annual FTL (fixed term license) for DB2 Express is licensed per server and increases resource limits to 8 CPU cores and 64 GB RAM (as of v10.5) and adds high availability pack. This pack includes: HADR (active–passive cluster solution), provides asynchronous replication, ACS (Advanced Copy Services) for storage-based (snapshot) data backup and restore, online table reorganizations and federation support for other DB2 servers. For HADR or replication you must have one FTL license per server. With DB2 Express you can get standard DB2 support features: access to regular DB2 fix packs, access to DB2 tech and phone support, and access to old but still supported DB2 versions.
- "Download DB2 Fix Packs by version for DB2 for Linux, UNIX and Windows". Retrieved December 16, 2018.
- "Column-organized tables". IBM. Retrieved September 13, 2017.
- Eaton, Chris. "Actionable Compression in Db2 10.5 with BLU Acceleration". Toolbox. Retrieved September 13, 2017.
- "RDF application development for IBM data servers". IBM. Retrieved September 13, 2017.
- "JSON application development for IBM data servers". IBM. Retrieved September 13, 2017.
- "About IBM DB2 Express-C". IBM. April 2009. Retrieved 2009-04-07.
- "Which distributed edition of DB2 10.5 is right for you?". IBM. April 2015. Retrieved 2016-03-26.