Re: Add a ROWCOUNT to the output of a select.
| От | Robins Tharakan |
|---|---|
| Тема | Re: Add a ROWCOUNT to the output of a select. |
| Дата | |
| Msg-id | 36af4bed0805131818p147bb440oa4c1944939e3b313@mail.gmail.com обсуждение |
| Ответ на | Add a ROWCOUNT to the output of a select. (Gavin 'Beau' Baumanis <gavinb@eclinic.com.au>) |
| Список | pgsql-sql |
While we could always check for the query performance reasons, I rather think that this is an overkill for the purpose of mere line numbers.
If such queries don't change frequently, you could be better off using a simple function that instead adds a 'rownumber' field to the output of the inner SQL query. The 'rownumber' could instead be calculated by simply incrementing it within a FOR loop for each row.
Robins
If such queries don't change frequently, you could be better off using a simple function that instead adds a 'rownumber' field to the output of the inner SQL query. The 'rownumber' could instead be calculated by simply incrementing it within a FOR loop for each row.
Robins
On Wed, May 14, 2008 at 5:24 AM, Gavin 'Beau' Baumanis <gavinb@eclinic.com.au> wrote:
Hi Everyone,
After spending some time searching through our good friend Mr. Google and the mailing list I found a post that provided me with a query that does just what I need.
However, the query takes FOREVER and although this is stated in the original mail I thought I would ask if there was any advice that you might be able to provide to speed things up a little.
And while the query does return over 27,000 rows in my case, I didn't expect it to take 9 minutes and 11 seconds!
Please find the query below - and of course - thanks in advance for any assistance you might be able to provide me with!
select
(select
count(*)
from
myTable as myCount
where
myCount.contactdate <= myTable.contactdate
) as rownum,
contactdate
from
myTable
where
contactdate > '2007-06-30 23:59:59'
order by
contactdate;
-Gavin
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