Re: count(rowid) vs count(*)

From: Andy Marden <amarden_at_altavista.net>
Date: Mon, 12 Jul 1999 13:42:40 +0100
Message-ID: <3789E2C0.F05EB6E6@altavista.net>

Tests that I ran - a while back now, must be on 7.1 I guess, showed this to be untrue, and that count(*) performed better than count(1). Maybe this has been optimised (it would make sense wouldn't it?)

Andy

Roger Jackson wrote:
>
> Hi,
>
> I was reading an article just recently which stipulated that you should not
> use count(*) to determine the number of rows in a table, but use count(1) or
> count(ROWID) instead. These options are faster because they bypass some
> unnecessary operations in Oracle's SQL processing mechanism.
>
> Can somebody explain to me why this would be faster and what mechanisms are
> bypassed.
>
> TIA
>
> Roger
Received on Mon Jul 12 1999 - 07:42:40 CDT