Re: Maximum height of an Oracle B-tree index
- From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Wed, 17 Mar 2004 22:46:31 -0000
Notes inline;
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk
The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
April 2004 Iceland
June 2004 UK - Optimising Oracle Seminar
----- Original Message -----
From: "Tanel Poder" <tanel.poder.003@xxxxxxx>
To: <oracle-l@xxxxxxxxxxxxx>
Sent: Wednesday, March 17, 2004 8:43 PM
Subject: Re: Maximum height of an Oracle B-tree index
: Hi!
:
: > Got to a blevel of 20. There is rumored to be hard limit
: > of 23 levels on a b*tree index as implemented by Oracle,
: > maybe I will give that a try later.
:
: I remember a max height of 22 from 8i Data Server Internals materials, but
I can check it when I get home in few weeks.
:
: Of course testing it out would be the best way to find the limit.
:
This would require a 4M block, 8GB index
in the smallest possible test, of course.
Here's a thought - is there a 4M (power(2,22))
block limit on a single segment ? I didn't think
so, but it is the limit on the number of blocks
in a single file. Might this have anything to do
with a height limit of 22 which is, after all, an
odd height since it isn't anything to do with a
number of bits being set.
(So far I've got to height 17, but I might leave
an all-nighter running to see if I can hit 22).
: Tanel.
----------------------------------------------------------------
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
-----------------------------------------------------------------
Other related posts:
