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Oracle Tips by Burleson |
10g Time Model Statistics
dba_hist Views
Time model statistics show the amount of CPU time that has been
required to complete each type of database processing work. Examples
include sql execute elapsed time, parse time elapsed and PL/SQL
execution elapsed time statistics.
The most important time model statistic is DB time, which represents
the total time spent by Oracle to process all database calls. In
fact, it describes the total database workload. DB time is
calculated by aggregating the CPU and all non-idle wait times for
all sessions in the database after the last startup. Since it is an
aggregate value, it is actually possible that the DB time statistic
could be larger than the total instance runtime.
One common objective in Oracle performance tuning is the reduction
of database workload or DB time. This reduction can be achieved by
minimizing specific components such as the session’s SQL parse and
processing times, session’s wait times, etc.
The above book excerpt is from:
Oracle
Tuning Power Scripts
With 100+ High Performance
SQL Scripts
Oracle In-Focus Series
ISBN
0-9744486-7-2
Mike Ault, Donald K.
Burleson. Harry Conway
http://www.rampant-books.com/book_2005_1_power_tuning.htm |
