Re: index Vs bitmap index

From: Ken Geis <kgeis_at_ucsee.EECS.Berkeley.EDU>
Date: 1998/02/26
Message-ID: <6d4scn$r42$1@agate.berkeley.edu>#1/1

In article <34F39654.7B38_at_p3.net>, Jerry Gitomer <jgitomer_at_p3.net> wrote: ...
>B-tree style indexes are very fast with the number of accesses being 2
>to the nth (where 2 to the nth is the smallest power of 2 larger than
>the number of rows being indexed). When dealing with columns with a very

Although this will enlighten you little on bitmap indexing, I have to make a clarification.

I think Jerry meant to say log(n). And again, it's actually a bit more complex than that. For all intents and purposes, though (since CPU is usually so much faster than disk) this is enough.

Also, basing your exponent on 2 would describe a binary search tree. A B+tree (B+trees have replaced B-trees to the extent that now they are almost synonymous) will give log(n) (base >2) performance.

Ken Received on Thu Feb 26 1998 - 00:00:00 CST