Re: Help:Index performance issue

From: Galen Boyer <galenboyer_at_hotpop.com>
Date: 26 Jul 2001 23:20:17 -0500
Message-ID: <uvgkex2ja.fsf@verizon.net>

On Tue, 22 May 2001, u518615722_at_spawnkill.ip-mobilphone.net wrote:

> When we run explain plan for it, there is
> no full table scan, which means the sql
> does not have any problem, right?

Full table scans are not evil. Try to think of index's as tables as well. To use an index, the database must read the values stored in the database to decide what rows it must go after from the table and then go get them from the actual table. These TWO lookups can be much more time consuming than just looking at the entire table.

-- 
Galen Boyer
It seems to me, I remember every single thing I know.

Received on Thu Jul 26 2001 - 23:20:17 CDT