Sorry, Didn't quite finish before hitting <ret> : It would be an interesting experiment to see if there : is any sort of general visual image that people use in : response to the word "unbalanced". I suspect that : many people would think of a set of old-style scales : with one side hanging down further than the other. : Conversely, I don't think many people would have : an image of (something like) a plank tipping because : a fulcrum was off-centre. : Apply these images to the expression 'unbalanced indexes', and I think you'll agree that the more (likely to be) popular image is exactly the wrong one for B-trees, and the (probably) less popular one is nearly an adequate one. Regards Jonathan Lewis http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/seminar.html Optimising Oracle Seminar - schedule updated Sept 19th ----- Original Message ----- From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx> To: <oracle-l@xxxxxxxxxxxxx> Sent: Saturday, November 13, 2004 8:36 AM Subject: RE: Index rebuilding : : Regarding specifically the sentence: : : :: So if you're looking at the diagram with : a whole :: pile of 25% full or 50% full buckets toward the left and all full or : nearly :: full buckets toward the right, I'd call that unbalanced. : : : You shouldn't. : : When talking about "Balanced B-trees", you need to honour : the technical meaning of word "Balanced" in the context that is : being used, otherwise you confuse the issue. : : -- //www.freelists.org/webpage/oracle-l