Re: normalization
- From: "Ryan" <ryan_gaffuri@xxxxxxxxxxx>
- To: <steve.adams@xxxxxxxxxxxx>
- Date: Tue, 1 Nov 2005 23:16:41 -0500
Steve,
Do you know a way to take the data you presented and do a test to show how
much additional CPU usage this will require under specific conditions?
if the trigger is fired 'X' number of times in a certain period, how much
increased CPU will I need?
How much will this reduce response time and/or scalability?
If I was to present this to a manager, I would typically need to show
something more tangible. Just because certain data elements that I gather
from the data dictionary increase, does not mean it will cause a problem for
us. So I would need to show realistic estimates.
any ideas on how to do this type of test?
----- Original Message -----
From: "Steve Adams" <steve.adams@xxxxxxxxxxxx>
To: <davewendelken@xxxxxxxxxxxxx>
Cc: "'Oracle-L Freelists'" <Oracle-L@xxxxxxxxxxxxx>
Sent: Tuesday, November 01, 2005 10:38 PM
Subject: RE: normalization
Hi David,
The difference can be demonstrated with a small test.
This is 10.2.0 with _in_memory_undo = false to show the redo.
SQL> connect test/test
Connected.
SQL> create table test (key number);
SQL> insert into test (key) values (1);
SQL> create trigger test before update on test for each row begin null;
end;
2 /
SQL> connect test/test
Connected.
SQL> update test set key = key + 1;
SQL> select n.name, m.value from sys.v_$mystat m, sys.v_$statname n
2 where m.value > 0 and n.statistic# = m.statistic# and bitand(n.class,
2) > 0;
NAME
VALUE
---------------------------------------------------------------- ----------
redo entries
2
redo size
632
SQL> drop table test;
SQL> create table test (key number);
SQL> insert into test (key) values (1);
SQL> create trigger test after update on test for each row begin null;
end;
2 /
SQL> connect test/test
Connected.
SQL> update test set key = key + 1;
SQL> select n.name, m.value from sys.v_$mystat m, sys.v_$statname n
2 where m.value > 0 and n.statistic# = m.statistic# and bitand(n.class,
2) > 0;
NAME
VALUE
---------------------------------------------------------------- ----------
redo entries
1
redo size
432
SQL>
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