Re: slow query execution

On Wed, May 30, 2007 at 08:56:45AM -0700, Trigve Siver wrote:
> Hi all,
>
> This query executes very slow:
>
> select (select count(*) from customer where id <= a.id) as row, id,
> from customer as a order by id;

So you are trying to get the ordinal position of every ID in the
table? I'm not surprised it takes a long time -- you have to join
the whole table to itself and then do a lot of counting. Are you
just trying to get the "row number" for your query answer? You can
do this with a temporary sequence, among other approaches, more
cheaply.

A

--
Andrew Sullivan | ajs(at)crankycanuck(dot)ca
Users never remark, "Wow, this software may be buggy and hard
to use, but at least there is a lot of code underneath."
--Damien Katz