FreeLists / oracle-l / Re: normalization

["Ryan" <ryan_gaffuri@xxxxxxxxxxx>]

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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