Hi,
Thanks for reply, As you have mentioned I need to get row numbers for my query,
so when I make some other query with same data I will know which row number has
a particular ID. As you mentioned "You can
do this with a temporary sequence, among other approaches...". Can you point me
to some sources or give me some examples, please?
Thanks
Trigve
----- Original Message ----
From: Andrew Sullivan <[EMAIL PROTECTED]>
To: pgsql-sql@postgresql.org
Sent: Wednesday, May 30, 2007 6:45:53 PM
Subject: Re: [SQL] 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 | [EMAIL PROTECTED]
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
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