Re: More efficient ways to do a select count(*)
Date: Fri, 20 Mar 2009 12:08:46 +0100
Web applications often do this to implement "pagination". See also:
(co)Author: "Applied Mathematics for Database Professionals" http://www.RuleGen.com/pls/apex/f?p=14265:13
On Fri, Mar 20, 2009 at 11:58 AM, FmHabash <fmhabash_at_gmail.com> wrote:
> I see often times applications run such query on a high frequency basis and
> this seemingly harmless query becomes a top cpu consumer.
> For whatever reason applications need to do this, how else such query can
> written to avoid the FTS it often does.
> In a quick test, I saw doing count(primary key) is much faster and xplan
> shows index vs. FTS access path.
> For this particular issue, there is no PK on the table and using a UK does
> guarantee a not-null value.
> Any other ideas (parallel exec is not an option).