Download Note 3

Additional Topics
DDM
• Distributed Data Management files [ Type(*File) and Attr(DDMF)]
– objects that represent files that exist on a remote system.
• For instance, if your customer file exists on a remote system, you can create a DDM
file on the local system that specifically points to that customer file on the remote
system.
– DDM files provide an interface that lets you access the remote file just as if it
were on your local system.
• Can compile programs using the file, read records, write records, and update
records while the system handles the communications
DRDA
• Distributed Relational Database Architecture is an architecture that allows
you to access data in a distributed relational database environment by
using SQL statements in your applications.
• The architecture has been designed to allow distributed data access for
systems in like and unlike operating environments.
– This means that your applications can access data residing on homogeneous
or heterogeneous platforms.
DRDA & SQL
• Structured Query Language (SQL)  the most common data access
language for relational databases in the industry.
• SQL was chosen as part of DRDA because of its high degree of
standardization and portability.
• Distributed environment, [you want to access data at remote locations] 
the SQL requests are routed to the remote systems and they are executed
remotely.
• Prior to sending the remote SQL request, a DRDA application must
establish a connection with the remote relational database where the data
is located. This is the purpose of the CONNECT SQL statement provided
by DRDA