how does oracle determine underflow? In class the professor said that if = a block is less than 1/2 full the block is either merged with another blo= ck if it can fit, or the data is redistributed amongst multiple blocks. = Oracle doesn't have a pctused for indexes. The pctfree is the overflow. D= oes oracle use the 1/2 full line for underflow? = > = > From: Connor McDonald <hamcdc@xxxxxxxxxxx> > Date: 2004/02/06 Fri AM 08:20:29 EST > To: oracle-l@xxxxxxxxxxxxx > Subject: Re: RE: How does Oracle keep B-tree indexes to 3 levels? > = > x > / \ > x x > = > This is my pictorial representation of a simple b-tree index. A simple= r one follows: > = > x > = > hth > connor > = > --- ryan.gaffuri@xxxxxxx wrote: > academic textbooks have them. The si= lbershatz book 'database > systems concepts' has it in chapter > > 12. = > > > = > > > From: "Prem Khanna J" <jprem@xxxxxxxxxxxx> > > > Date: 2004/02/05 Thu PM 11:57:29 EST > > > To: <oracle-l@xxxxxxxxxxxxx> > > > CC: <cary.millsap@xxxxxxxxxx> > > > Subject: RE: How does Oracle keep B-tree indexes to 3 levels? > > > = > > > Hi Cary & List , > > > = > > > i have been long trying to get a pictorial representation > > > of a simple b-tree index and how it changes as the = > > > index grows . Though i read the docs , still i'm not > > > able to say "okay , this is how b-tree index works" . > > > = > > > Has anyone got something like what i'm looking for ? > > > = > > > Just curious to know : = > > > Cary , what does * Nullius in verba * mean ? = > > > = > > > Regards, > > > Prem. > > > = > > > >>-----Original Message----- > > > >>From: oracle-l-bounce@xxxxxxxxxxxxx = > > > >> > > > >>You get a new level only if the parent node splits propagate = > > > >>all the way > > > >>to the index root node. Jonathan Lewis and Steve Adams have some = good > > > >>tests in their courses that use block dumps to show how Oracle > > > >>redistributes keys in branch blocks when nodes split. > > > >> > > > >>Yes, Oracle index nodes are one block apiece. > > > = > > > >>Cary Millsap > > > >>* Nullius in verba * > > > = > > > ---------------------------------------------------------------- > > > Please see the official ORACLE-L FAQ: http://www.orafaq.com > > > ---------------------------------------------------------------- > > > To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > > > put 'unsubscribe' in the subject line. > > > -- > > > Archives are at //www.freelists.org/archives/oracle-l/ > > > FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > > > ----------------------------------------------------------------- > > > = > > = > > ---------------------------------------------------------------- > > Please see the official ORACLE-L FAQ: http://www.orafaq.com > > ---------------------------------------------------------------- > > To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > > put 'unsubscribe' in the subject line. > > -- > > Archives are at //www.freelists.org/archives/oracle-l/ > > FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > > ----------------------------------------------------------------- = > = > =3D=3D=3D=3D=3D > Connor McDonald > Co-author: "Mastering Oracle PL/SQL - Practical Solutions" - available = now > web: http://www.oracledba.co.uk > web: http://www.oaktable.net > email: connor_mcdonald@xxxxxxxxx > = > "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" > = > = > = > = > = > ___________________________________________________________ > BT Yahoo! Broadband - Free modem offer, sign up online today and save =A3= 80 http://btyahoo.yahoo.co.uk > ---------------------------------------------------------------- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > ---------------------------------------------------------------- > To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx > put 'unsubscribe' in the subject line. > -- > Archives are at //www.freelists.org/archives/oracle-l/ > FAQ is at //www.freelists.org/help/fom-serve/cache/1.html > ----------------------------------------------------------------- > = ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------