IBM AS/400e User Handbook Manual page 578

IBM Licensed Programs: Database Products
With DB2 DataJoiner, application developers and database administrators have greater
flexibility in distributing data and applications across various platforms:
DRDA Application Server: The Distributed Relational Database Architecture (DRDA)
Application Server (AS) capability allows DB2 for MVS, DB2 for VSE and VM (SQL/DS), and
DB2 for OS/400 applications (or any other application that implements the DRDA Application
Requestor functionality) to access data located in any of the supported data sources (Oracle,
Sybase, and so forth). The DRDA AR support can function across SNA or TCP/IP, and DRDA
AS support can function across SNA. With this capability, thousands of existing database
applications running on the MVS, VSE, VM, and OS/400 platforms can access data stored in
workstation databases. As an example, QMF, in conjunction with DB2 DataJoiner, can now
provide access to DB2 and non-DB2 data sources.
Distributed Unit of Work: Distributed Unit Of Work (DUOW) functionality, also known as
Two-Phase Commit, provides the capability for an application to read or update tables in
more than one database from within a single unit of work with full data integrity.
For example, it is possible to query tax tables in a DB2 for MVS database and concurrently
update an Oracle for HP-UX payroll database. Or, money withdrawn from a bank account in
one country can be deposited into an account in another during the same transaction.
Because these multiple units of work are performed during the scope of a single global
transaction, the integrity of the data is assured via Two-Phase Commit feature, even in the
case of equipment failure.
Note: On DB2 DataJoiner, Two-Phase Commit is only be supported on those data sources
that natively support Two-Phase Commit.
The replication features of DB2 DataJoiner are fully compatible with the DataPropagator
log-CAPTURE and APPLY components for the DB2 Family as well as DataPropagator
Non-Relational for IMS.
IBM's replication offers transaction consistency, condensing of hot spot updates to minimize
network traffic, change propagation through DB2 views (including join views), and update
anywhere replication between DB2 databases with transaction conflict detection and
automatic compensation.
DB2 DataJoiner extends this capability with database transparency and automatic generation
of change capture triggers for Oracle, Microsoft SQL Server, Informix, Sybase, and Sybase
SQL Anywhere.
Where triggers are used to capture changes, the tables used to process these changes can
be in different distributed tables to avoid a single point of failure. The processes that apply
changes to targets can execute locally or on a remote system, offering the same rich function
regardless of their location in the network. For example, one such process executing on a
Windows NT system provides the same function as it would executing on an MVS system!
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AS/400e System Handbook