Quad/Tech International, Sussex, WI USA
> -Original Message-
> From: Rachel Carmichael [mailto:wisernet100@;yahoo.com]
> Sent: Tuesday, November 12, 2002 6:48 PM
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Is nothing sacred? (Oracle vs The Experts)
&g
Mark,
I saw and read the thread and I've read the paper.
Dan was talking about how in '99 Oracle was preaching 15% and I told
what I had been told, by Oracle in 2000. Two years makes an awfully
large difference in what the party line is and becomes.
And I also said that I don't follow that as
Title: RE: Is nothing sacred? (Oracle vs The Experts)
> that the Cubs will never win another
> World Series (okay...bad example).
Ok, now that hurt.
Matt "long suffering cubs fan" Adams
"Do they still play the blues in Chicago when baseball
season rolls around
Connor,
Didn't you win a price? Like SmartDBA 2002?
Anjo ;-)
-Original Message-
McDonald
Sent: Wednesday, November 13, 2002 12:41 AM
To: Multiple recipients of list ORACLE-L
for a wonderful laugh download the TUSC (very recent)
Oracle 9i performance tuning slides where there is a
slide
Rachel,
In case you missed the mention earlier in the thread, go to
http://www.hotsos.com/ and click the "Knowledge On-line" link and look
for a paper called "When to use an index". Cary does an excellent job
explaining why row selectivity is a totally invalid criteria. He then
proceeds to demon
last time I checked with an Oracle University instructor who I trust as
knowledgeable, it was FTS if more than 5-8% of rows expected to be
returned. This was 2000. These days, who knows?
I don't go by the rules much anymore but by perception of performance
and by explain plan analysis.
--- "Fin
for a wonderful laugh download the TUSC (very recent)
Oracle 9i performance tuning slides where there is a
slide that is titled (something like)
"The 15% rule is back"
talking directly about amount of data returned via an
index...
dear oh dear oh dear...
then there is also the "awesome" advice
Of course, sacred cows make the best steaks (sorry, Gaja).
An excellent example is the age old ideas that the earth was the center of
the universe, that the world was flat, that the Cubs will never win another
World Series (okay...bad example). Knowledge is limited by what we can
currently test. W
istrator
[EMAIL PROTECTED] Quad/Tech International, Sussex, WI USA
> -Original Message-
> From: Cary Millsap [mailto:cary.millsap@;hotsos.com]
> Sent: Tuesday, November 12, 2002 3:24 PM
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Is nothing sacred? (Or
I think the question "Is nothing sacred?" is an interesting one. Lots of
these things we're talking about have been false for a very long time.
It's only that people are finally starting to notice them. Product
changes are often *not* what's driving "new knowledge." In many cases,
the "change" that
Rich,
I think the answer to your question #1 is, "Because a lot of people
aren't careful." They repeat something because they heard or read it, or
because they tried it once and it worked. Trying something once and
seeing it work is not sufficient to prove a cause-effect relationship.
The index th
> > From: DENNIS WILLIAMS
> [mailto:DWILLIAMS@;LIFETOUCH.COM]
> > Sent: Monday, November 11, 2002 2:04 PM
> > To: Multiple recipients of list ORACLE-L
> > Subject: RE: Is nothing sacred? (Oracle vs The
> Experts)
> >
> >
> > Rich - Actually, if you t
ients of list ORACLE-L
> Subject: RE: Is nothing sacred? (Oracle vs The Experts)
>
>
> Rich - Actually, if you took an Oracle Performance Tuning
> class from Oracle
> Education right now, you would find the BHR mentioned little
> and Oracle
> waits emphasized a great deal.
Rich - Actually, if you took an Oracle Performance Tuning class from Oracle
Education right now, you would find the BHR mentioned little and Oracle
waits emphasized a great deal. I took that class about a month ago and the
instructor described how Cary had prevailed in convincing the people at
Orac
"Jesse, Rich" wrote:
>
> So, there I am, on 8.1.7.2 (and .4) on HP/UX 11.0, with a process that runs
> 20 minutes out of every hour of the day (despite my protests to it's
> design). After it starts having problems (go figure), it becomes a priority
> to speed it up.
>
> Thanks to a 10046 trace,
Marlene and I did "exploding the myths" a while back and Jeremiah
Wilton did a myths presentation at OOW last year as well.
Rachel
--- Jeffery Stevenson <[EMAIL PROTECTED]> wrote:
> Well, besides the paper you found, Jonathan Lewis has a myths section
> with
> his site:
> http://www.jlcomp.demon.
Well, besides the paper you found, Jonathan Lewis has a myths section with
his site:
http://www.jlcomp.demon.co.uk/myths.html
Gaja also has a good "myths" article:
http://www.quest-pipelines.com/newsletter-v3/0302_F.htm
Rachel, weren't you doing a presentation on Oracle myths (or did you just
put
Find Cary's paper about misunderstanding Oracle index internals. It spells
out the % Of Rows Returned fallacy. The key issue is that Oracle does not
read rows, it reads blocks. If 10% of the rows of interest are scattered
among 95% of the blocks, is it better to index or use FTS? If 25% of the
rows
18 matches
Mail list logo
