DB2 for z/OS and WebSphere: The Perfect Couple

8 DB2 for z/OS and WebSphere: The Perfect Couple

Figure 1-1 Basic data flow in a DB2 subsystem from z/OS and distributed environments

A request from a distributed environment is very similar to the data flow originating from within

a z/OS environment (local attachment). The significant difference is using the DDF address

space to establish a connection as opposed to an attachment facility.

This is also the case when using JDBC Type 4 connectivity provided by the IBM DB2

Universal JDBC Driver to connect to a DB2 for z/OS subsystem. In this scenario, the

Universal Driver is acting as a DRDA® application requester to establish a connection into

the DDF address space (acting as a DRDA application server) of the DB2 for z/OS

subsystem. This is discussed in more detail in “Accessing DB2 from a Java environment” on

page 19.

1.4 DB2 data structures

DB2 data structures can be conceptualized as a hierarchy of objects that have at least one

relationship to another object. Figure 1-2 on page 9 illustrates a basic relationship between

the DB2 data structures.

TSO

attachment facility

IMS

attachment facility

CICS

attachment facility

CAF

RRSAF

z/OS

environment

Distributed

environment

DDF

address space

MSTR

address space

DBM1

address space

IRLM

address space

DB2 OS/390 or z/OS subsystem