Section 1.6. Host Connectivity

1.6. Host Connectivity

DB2 Connect is the software product containing the licensed files required to communicate from a DB2 distributed client, also known as the DRDA Application Requester , to a host DB2 server, a DRDA Application Server . (DRDADistributed Relational Database Architectureis the standard that defines formats and protocols for providing transparent access to remote data.) Host DB2 servers include DB2 UDB for z/OS and OS/390, DB2 UDB for VM/VSE, and DB2 UDB for iSeries. DB2 Connect also includes a DB2 runtime client.

As indicated earlier, if you install DB2 UDB ESE there is no need to install DB2 Connect since DB2 UDB ESE comes with a DB2 Connect component.

NOTE

DB2 Connect software is only required when communicating from a workstation to a host; it is not required in the other direction (from a host to a workstation).

DB2 Connect comes in two main flavors.

The Personal Edition supports the direct connection of one DB2 client to multiple host DB2 servers.
The Enterprise Edition supports the connection of multiple DB2 clients to multiple host DB2 servers via a DB2 Connect server.

1.7. Federated Support

Federation allows you to query and manipulate data stored on other servers and in other RDBMSs. When you issue an SQL statement in a federated environment, you may actually be accessing information from multiple databases and potentially multiple RDBMSs (see Figure 1.10).

Figure 1.10. DB2 federation

Federated support is included in DB2 when the other databases being accessed are part of the IBM DB2 family, that is, another DB2 database or an Informix database. For accessing databases from other vendors , refer to the IBM DB2 Information Integrator product described in section 1.9.

1.8. Replication Support

Replication lets you propagate data to different servers to keep different databases synchronized. Data changes captured at one server are later applied to another (target) server, as illustrated in Figure 1.11. In the figure, the first box shows the source server and the fourth box shows the target server. The second and third boxes contain the "capture" and "apply" components , respectively.

Figure 1.11. DB2 replication environment

DB2 UDB has built-in support for replication when source and target databases are part of the IBM family, which includes Informix. For databases from other vendors , such as Oracle or SQL Server, the IBM DB2 Information Integrator software is required.

1.9. IBM DB2 Information Integrator

The IBM DB2 Information Integrator ( II ) provides federated support by masking databases from IBM or different vendors as if they were part of the same database. The II uses wrappers to communicate with and retrieve data from these other data sources; II encapsulates any conversions required from the source database and presents them to the target database as tables.

The Replication Edition of IBM DB2 Information Integrator supports the propagation of data between DB2 UDB, Microsoft SQL Server, Oracle, and others.

1.10. Special Package Offerings for Developers

Two special offerings are available for application developers.

The DB2 Personal Developer's Edition (PDE), for Linux and Windows platforms, comes with DB2 UDB Personal Edition, DB2 Connect Personal Edition, and all the DB2 clients .
The DB2 Universal Developer's Edition (UDE), for Linux, UNIX, and Windows platforms, comes with all server editions, with the exception of the database partitioning feature and optional extenders. In addition, all the DB2 clients are also provided.

Both editions come at a reduced price, and are restricted to the development, evaluation, demonstration, and testing of application programs. Figure 1.12 shows most of the software provided with each offering. For a detailed listing of the features included with each offering, refer to the DB2 for Linux, UNIX, and Windows main Web page at http://www.ibm.com/software/data/db2/udb/.