First Look at
DB2 9.7
New features improve
performance and compatibility
and are easy to implement
David Beulke is former president
of IDUG ( www.idug.org) and a
DB2 Data Champion. He has
more than 22 years experience
in architecture, design, and
development of high-performance
DB2 data warehouse and OLTP
systems across all platforms.
i
r
The new release of IBM DB2 9.7 for Linux, UNIX, and Windows offers many advan- tages for better performance, better maintenance, and lower total cost of
ownership, especially for large and
robust databases. But after exploring
the new version myself, what strikes me
most about the features is how easy they
are to implement.
The first feature that makes this
elease really stand out is index compression, which reduces both I/O and the size
of the index structure. Through this new
compression technology, DB2 is capable
of achieving compression ratios as high as
50 percent or more. This index size reduction has big implications for dramatically
reducing disk requirements for terabyte
data warehouse implementations and for
reducing overall I/O and response time for
transaction systems. With this feature, DB2
is keeping well ahead of the competition.
The next new feature within DB2 is an
mprovement to its transaction concurrency
model. This concurrency enhancement
provides more granularity for the transactions. Within some high-performance
systems, one transaction writing data and
another transaction reading data can be
blocked or delayed before the writer transaction is committed. This delay or blocking
situation can cause some high-performance
ti
systems issues, so the DB2 team developed a new isolation level called Currently
Committed that is now the default within
the system.
The new Currently Committed isola-on level allows writer transactions to
continue processing while the other reader
transactions within the system get their
data. It works by retrieving the data row
Your application developers
will like the new scalar
functions, especially the
date and time functions that
will provide performance
boosts for processing.
i
information that the reader transaction
needs from the DB2 logs—usually from the
log’s memory cache, which is very fast. As a
result, the reader transaction can continue
processing without waiting for the writer
transaction to be committed. This functionality provides more robust concurrency and implements it in a way that does
not cause extra overhead for the system or
transaction processing.
New releases of DB2 almost always
nclude SQL improvements, and version 9.7
has many SQL-related features that improve
f
a
functionality, compatibility, and overall
performance. Your application developers
will like the new scalar functions, especially the date and time functions that will
provide performance boosts for processing.
There are too many to mention here, but
your development group should immediately evaluate the extensive number of new
SQL functionalities.
Next, a number of new phrases were
dded to the DB2 lexicon to make it more
compatible with Oracle SQL syntax and
PL/SQL. The improvements should enable
you to migrate Oracle applications to DB2
in days rather than months. Plus, the ability
to use the same SQL syntax will allow your
development team to quickly shift to the
DB2 platform with its self-tuning and automated memory management.
These are only some of the DB2 9.7
eatures; more information can be found
at ibm.com/db2/9. Many of these features
were hot topics at the International DB2
User Group conference in Denver, held in
May 2009. The conference included many
great presentations by beta customers,
consultants, and IBMers, talking through
the internals as well as implementation and
performance details. If you weren’t able to
attend, look at the presentation grid at
www.idug.org/conference/CD/NA09/grid.
html and buy the conference CD.
