I like to think of it this way: If a table is defined as "small" when it does not need to be indexed, then there is no such thing as a small table
Others didn't mention - but you may want to look at using IOT's for some of the cases you've mentioned Cheers Connor --- "Jesse, Rich" <[EMAIL PROTECTED]> wrote: > Actually, I did know about the BHR thing, primarily > from this list, just as > you did. It was the indexing one that cought me > off-guard. I was just > using the former as a reference. > > Speaking of which, your Don Quixote reference is > priceless! "Facts are the > enemy of truth." :D > > Rich Jesse System/Database > Administrator > [EMAIL PROTECTED] Quad/Tech > International, Sussex, WI USA > > > -----Original Message----- > > 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 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 > > Oracle that counted and the class materials were > being > > rewritten for the > > next class after mine. > > Well, being a computer professional is a hard > burden, what with the > > underlying assumption ever changing. Actually, > given the extensive > > discussions we've had on this forum about BHR vs. > waits, I'm > > surprised it > > caught you unawares. This was where I'd first > heard about the > > new emphasis > > on waits. Of course, with waits becoming the > conventional > > wisdom, Cary and > > others will have to find another windmill to tilt > at. Cary - > > anything lined > > up? > > Dennis Williams > > DBA, 40%OCP > > Lifetouch, Inc. > > [EMAIL PROTECTED] > > > > > > -----Original Message----- > > Sent: Monday, November 11, 2002 10:58 AM > > To: Multiple recipients of list ORACLE-L > > > > > > 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, we see that the query > taking the > > most elapsed time > > does FTSs on each of two very small tables (1 > block and 4 blocks -- 8K > > blocksize). These tables are not indexed, as per > the official Oracle > > recommendation. After reading the excellent > Hotsos paper > > "When to index a > > table" (THANKS, CARY!), I added an index to reduce > elapsed > > time on this > > query by 50% (150 to 75 seconds in test), proving > to me that > > the paper is > > valid. And I've only read to page four! > > > > OK, first I'm taught by Oracle to look at Buffer > Cache Hit Ratios as a > > measure of performance, then told (and thoroughly > convinced) > > by experts that > > this is bunk. Now, I found out that the 15% (or > 10% or > > whatever, depending > > on version) ratio of rows returned to total rows > in > > determining when to use > > an index in a query is garbage. > > > > 1) Why is this? > > > > 2) What other pearls of performance wisdom from > Oracle Corp should I > > completely disregard as false? > > > > I know there's an Oracle Fallacy website > somewhere... > > > > It just looks bad on me, our department, and > Oracle when, once again, > > something I've been preaching to our developers as > gospel > > turns out to be > > completely false. > > > > Maybe I'm grumpy because it's snowing on my leaves > right > > now... <sigh> > > > > > > Rich > -- > Please see the official ORACLE-L FAQ: > http://www.orafaq.com > -- > Author: Jesse, Rich > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 > http://www.fatcity.com > San Diego, California -- Mailing list and web > hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an > E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of > 'ListGuru') and in > the message BODY, include a line containing: UNSUB > ORACLE-L > (or the name of mailing list you want to be removed > from). You may > also send the HELP command for other information > (like subscribing). ===== Connor McDonald http://www.oracledba.co.uk http://www.oaktable.net "GIVE a man a fish and he will eat for a day. But TEACH him how to fish, and...he will sit in a boat and drink beer all day" __________________________________________________ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: =?iso-8859-1?q?Connor=20McDonald?= INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
