At 09:49 30-12-03 -0800, you wrote:
>
There are times when running a test harness
> through a single pl/sql is going to give you
> a spurious result because of extra pinning
> (of data blocks and library cache material)
> may confuse the issue.
That isn't a factor, as I never
use the results
from the first run for that very
reason.
Jared
Neither did I. But what wonders me is that even after the firest run
(preceded by a flush of the shared_pool) every subsequent run (whithout
flush, of course) gave other figures. The ones I included in my message
where the most representative figures of over 20 runs. I stopped
processes like vmware etc to get the system as stable as possible, but
differences stayed pretty significant.
Regards, Carel-Jan
===
If you think education is expensive, try ignorance. (Derek Bok)
===
"Jonathan
Lewis" <jonathan@jlcomp.demon.co.uk>
Sent by: ml-errors@fatcity.com
12/30/2003 03:29 AM
Please respond to ORACLE-L
To: Multiple recipients of list ORACLE-L <ORACLE-L@fatcity.com>
cc:
Subject: Re: pl/sql open cursor question
There are times when running a test harness
through a single pl/sql is going to give you
a spurious result because of extra pinning
(of data blocks and library cache material)
may confuse the issue.
Technically, if the implicit code and the explicit
code were written to do exactly the same thing,
then the implicit code should be faster because
of a couple of under-cover optimisations. (This
has been true for several years, I believe).
Currently (9.2.0.X-ish) there is a bug that I
recently found on metalink which says something
about the FETCHes from an implicit cursor using
more CPU than the FETCHes from an explicit
cursor.
Bottom line - test it in the environment where you
are using it, and on the version you are running in
production. In almost all cases, the difference will
probably be imperceptible, anyway.
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk
The educated person is not the person
who can answer the questions, but the
person who can question the answers -- T. Schick Jr
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http://www.jlcomp.demon.co.uk/tutorial.html
Three-day seminar:
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The Co-operative Oracle Users' FAQ
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----- Original Message -----
To: "Multiple recipients of list ORACLE-L" <ORACLE-L@fatcity.com>
Sent: Tuesday, December 30, 2003 10:49 AM
Jared,
Point taken. I should do some testing instead of publish an opinion. I
still do not like the constraction, but that's a matter of taste.
I have done some testing as well, because I think you were somehow
comparing apples and oranges: function a uses an implicit cursor, whereas
function b has an explicit cursor. So I ran a, b and b2 through Tom Kyte's
runstats harness, but found no significant differences:
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Received on Tue Dec 30 2003 - 14:24:25 CST
