Chapter14.Accessing Distributed Data

Chapter 14. Accessing Distributed Data

• Distributed data

• Coding methods for distributed data

• Programming considerations

• Remote query performance

The DB2 Distributed Data Facility (DDF) allows access to data held by other data management systems or makes your DB2 data accessible to other systems. A DB2 application program can use SQL to access data controlled by non-DB2 database management systems at which the application's plan is bound. This DB2 is known as the local DB2 or application requester (AR). Any DBMS that supports remote connectivity is called an application server (AS). Any application server other than the local DB2 is considered a remote server (RS), and access to its data is a distributed operation. DB2 provides two methods of accessing data at remote application servers: DRDA and DB2 private-protocol access. For application servers that support the two-phase commit process, both methods allow for updating data at several remote locations within the same unit of work.

The location name of the DB2 subsystem is defined during DB2 installation as stored in the BSDS. The communications database (CDB) records the location name and the network address of a remote DBMS. The tables in the CDB are part of the DB2 catalog.