DB2 UDB for z/OS Version 8 Performance Topics - IBM Redbooks

– Buffer pools and buffer pool control blocks
– EDM pool (DBDs and dynamic statement cache)
– Sort pool
– RID pool
– Castout buffers
– Compression dictionaries
A large address space of up to 264 bytes (16 exabytes) can now be defined for DBM1 and
IRLM address spaces. DBM1 replaces hiper spaces and data spaces with buffer pools. As
a result, managing virtual storage becomes simpler, and the scalability, availability, and
performance improves as your real storage requirements and number of concurrent users
increase. IRLM can support large numbers of locks.
► Schema evolution
As 24x7 availability becomes more critical for applications, the need grows for allowing
changes to database objects while minimizing the impact on availability. Online schema
evolution allows for table, index, and table space attribute changes while maximizing
application availability. For example, you can change column types and lengths, add
columns to an index, add, rotate, or rebalance partitions, and specify which index (the
partitioning index or non-partitioning index) you want to use as the clustering index.
► DB2 Universal Driver for SQLJ and JDBC
Organizations increasingly require access to data residing in multiple sources in multiple
platforms throughout the enterprise. More and more companies are buying applications
rather than database management systems, as database selection is being driven by
interoperability, price performance, and scalability of the server platform. The Universal
Driver for SQLJ and JDBC provides an open and consistent set of database protocols to
access data on the Linux®, UNIX®, Windows®, and z/OS platforms.
Tools and applications can be developed using a consistent set of interfaces regardless of
the platform where the data resides. End users can integrate their desktop tools and other
applications in a consistent manner with whichever databases (or multiple databases
concurrently) are in the enterprise. The objective of this enhancement is to implement
Version 3 of the Open Group DRDA Technical Standard. It eliminates the need for
gateways, improves desktop performance, and provides a consistent set of database
protocols accessing data from a z/OS server as well as UNIX and Windows servers.
► Unicode support
Architectural changes to DB2 V8 enhance the DB2 support for Unicode with SQL in
Unicode, Unicode in the DB2 catalog and the ability to join Unicode, ASCII and EBCDIC
tables. This means that you can manage data from around the world in the same SQL
statement. DB2 now converts any SQL statement to Unicode before parsing, and as a
result, all characters parse correctly.
► DB2 Connect and DRDA
DB2 Connect and DRDA remain the cornerstone for DB2 distributed processing, and V8
has many enhancements in this area. Enhancements in DB2 V8 remove roadblocks to
performance and DB2 family compatibility by providing support for Common Connectivity
and standardizing database connection protocols based on the Open Group Technical
Standard DRDA Version 3.
1.1.2 Usability, availability, and scalability
The main enhancements related to usability, availability, and scalability are:
► Online schema evolution
You can change data and indexes with minimal disruption.
Chapter 1. DB2 UDB for z/OS Version 8 3