With all
of the hoopla surrounding the impending
release of Oracle10g, it is sometimes
difficult to differentiate between the
truly valuable features and the marginal
new features. For more information on
Oracle10g new features, I recommend the
premier book
Oracle Database 10g new features,
by Mike Ault, Daniel Liu and Madhu Tumma.
On one hand, Oracle10g is more complex
and robust than previous database versions
with its wealth of new tuning options,
sophisticated tuning tools and enhanced
tuning parameters. On the other hand, it
is simpler than any Oracle database before
it. At your option, you can disable much
of the flexibility (and complexity) of
Oracle and create an easy to maintain
system that requires little experienced
human intervention.
10g provides a wealth of features that
can be used to automate almost every
aspect of its database administration. It
is important to note that these automation
features are optional, and they are
not intended to replace standard DBA
activities. Rather, the Oracle10g
automation features are aimed at shops
that do not have the manpower or expertise
to manually perform the tasks.
Let's take a closer look at my favorite 10g
new features.
Automatic Workload Repository
Automatic Workload Repository (AWR)
defaults to a collection interval every 30
minutes and collects data that is the
foundation for all of the other
self-tuning features. AWR is very much
like STATSPACK, especially the level-5
STATSPACK collection mechanism where top
SQL is collected every hour, based on your
rolling thresholds for high-use SQL. In
addition to the SQL, AWR collects detailed
run-time statistics on the top SQL (disk
reads, executions, consistent gets) and
uses this information to adjust the
rolling collection threshold. This
technique ensures that AWR always collects
the most resource-intensive SQL.
Automatic Maintenance Tasks
The Automatic Maintenance Tasks (AMT)
automate the routine tasks of refreshing
statistics when they become stale, and
rebuilding indexes when they become
sub-optimal. The AMTs are scheduled for
execution inside the new Oracle10g Unified
Scheduler (US), providing a primitive DBA
functionality.
Automatic Storage Management
The Automatic Storage Management (ASM)
feature allows for the automatic
stripe-and-mirror everywhere approach to
be used to automatically load balance the
disk I/O subsystem and remove the need for
the DBA to specify physical file locations
when allocating a tablespace.
Automated features aside, there are
other new 10g features that I find
especially intriguing.
Server Generated Alerts
Server Generated Alerts (SGA)
interfaces with the US to send e-mail
messages when an external problem is
impeding Oracle performance. External
problems might include a UNIX mount point
that is full, causing a failure of ASM
files to extend or a RAM shortage with the
System Global Area.
Summary
Oracle10g is one of the most important
new releases of Oracle in many years. The
advent of Oracle10g will definitely
broaden the footprint of Oracle in the
small to mid-sized market, plus provide
the Oracle DBA with a wealth of
highly-intelligent new features to
simplify database administration.
