 |
|
Oracle Tips by Burleson |
Easy Oracle Automation
Chapter 4 -
Automatic Workload Repository and Automatic Database
Diagnostic Monitor
Base Statistics, Metrics, and Statistics
Levels
BASIC is the computation of the AWR statistics
with metrics turned off. TYPICAL is the default value and collects
only part of the statistics. It represents what is typically needed
for 10g administration. Setting the parameter to ALL will retain all
the statistics.
A baseline is defined on a pair of snapshots to
tag sets of data for important time periods. Each baseline is unique
for one and only one pair of snapshots. A baseline is identified by
a user created name or a system generated identifier. A baseline can
be manually named by running the create_baseline procedure
and by specifying a name and a pair of snapshot identifiers.
A baseline identifier is assigned to the
newly created baseline, which is unique for the life of the
database. Baselines are used to retain snapshot data for
comparison with current system behavior and the set up of
threshold based alerts.
The MMON process purges
all older snapshots on a nightly basis to make room for new
statistics. Snapshots are removed in chronological order.
Snapshots pertaining to baselines are retained until the
baselines are removed. MMON tries to limit its purge task in
the management window defined by the DBA. The amount of
historical AWR statistics can be controlled by setting a
retention period.
The above text is
an excerpt from:
Easy Oracle Automation
Oracle10g Automatic
Storage, Memory and Diagnostic Features
ISBN 0-9745993-6-0
by Dr. Arun Kumar R.
|
Download your Oracle scripts now:
www.oracle-script.com
The
definitive Oracle Script collection for every Oracle professional DBA
|
|
