Chapter 2. The evolution of DB2 for z/OS 33
Intelligent Resource Director and Workload Manager continuously track activity
and direct work and resources in a manner which ensures that business
service-level agreements are met. Workload throughput is maximized and “white
space” is minimized.
This environment is mature and sophisticated. Extensive autonomic features of
the operating system ensure that resources are continually monitored. This is
about the server being up. It is about the application and the data and the
connection to disk being up. This environment offers extreme availability. New
high priority work can be added and immediately serviced adequately at the
expense of lowest priority workloads. This is truly unique in the industry. It is the
substance that ensures data is available on demand. You can learn more in 3.9,
“WorkLoad Manager, Intelligent Resource Director, and VIPA” on page 63.
2.2.2 Near-linear scalability
DB2 in a Parallel Sysplex configuration offers tremendous near-linear scalability.
You can scale vertically within a server or horizontally across the group. Within
the zSeries architecture, the cost of adding a member to an existing group is
minor. For more information about sysplex timers and the coupling facility, both
key components of zSeries, see 3.2, “Parallel Sysplex and data sharing” on
page 43, and 3.2.6, “Summary” on page 48.
2.2.3 Preservation of investment
IBM works hard a preserving the investment that you have in you application
software and database structures. See 3.11, “zSeries 990” on page 75.
When you upgrade from one version to another, the design strategy is to ensure
that existing code executes successfully without any changes. The few
necessary incompatibilities that exist are highlighted early. IBM identifies and
describes these in a timely manner allowing you to proactively research and
adjust where necessary. Where practical, IBM provides automated scripts to
IBM has provided ample notification of upcoming changes which demand
change in database structure or application coding. For example the deprecation
of type 1 indexes was announced at least two versions before it took effect.
Similarly there have been numerous announcements about the future demise of
private protocol. In both cases, the alternatives, type 2 indexes and DRDA
protocol, enabled a much higher level of usability and performance.