IBM DB2 Express-C
|Stable release||DB2 Express-C (10.5) / June 17, 2013|
|Written in||C, C++|
|Website||DB2 Express-C homepage at ibm.com|
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"), and 10.5 (codename "Kepler").
IBM DB2 Express C supports 32bit and 64 bit x86 Windows XP, Vista and Windows 7, (with some issues in Windows 7). Linux version runs on 32bit and 64bit 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 does not limit the amount of data that can be stored in a database (as of v10.5 it is a 15TiB limit), nor does the database engine 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 16GB RAM (increase from 4GB 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 Fixpacks 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 fixpacks, 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 fixpack. 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 feature were moved to DB2 Express product instead with price tag unchanged. For upgrading DB2 Express-C to DB2 Express you need to reinstall DB2. Deinstalling 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 $2150 per server. FTL license doubles limits to 4 CPU cores and 8 GB RAM (as of v10) and adds high availability pack. This pack includes: HADR (Active - Passive cluster solution), provides asynchronous replication, online table reorganizations and federation support for other DB2 servers. For HADR or replication you must have one FTL license per each server. With DB2 Express you can get standard DB2 support features: access to regular DB2 Fixpacks, access to DB2 Tech and phone support, and access to old but still supported DB2 versions.