||Oracle Tips by Burleson
Chapter 7 - Tuning and Performance
OCP Instructors Guide for
Oracle DBA Certification
Performance Tuning Intelligent Advisories
Experienced DBAs often start their tuning
efforts by selecting data from the V$ dynamic performance tables to
view system-wide performance indicators. For those of you new to
Oracle, statistics are pieces of information that the Oracle
instance collects to help administrators gauge performance and
identify problems. But intelligent performance advisories are a
relatively new concept (they are introduced in Oracle9i), so a quick
definition is in order before we continue.
An advisory is a collection of information that
predicts the impact a specific change would have on the item being
monitored. Advisories allow administrators to simulate "what if"
hypothetical scenarios to predict the impact a specific change may
have on the Oracle environment.
For example, the v$shared_pool_advice view contains information about
estimated parse time savings if a different shared pool size were
used. Each row in the view contains a percentage value (ranging from
50 percent to 200 percent of the current shared pool) and the
estimated performance increase or decrease associated with that
percentage of change.
The above text is
an excerpt from:
OCP Instructors Guide for Oracle DBA Certification
A Study Guide to Advanced Oracle Certified Professional Database
by Christopher T. Foot
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