Re: URGENT! How many rows will be returned?

From: <cbdinh_at_hotmail.com>
Date: Thu, 21 Oct 1999 10:27:10 GMT
Message-ID: <7umppm$p3t$1_at_nnrp1.deja.com>


Hi,

You can create triggers on those tables. The triggers will store the number of rows that meet your search conditions to 3rd table. Then you can access the 3rd table to get the number.

The performace of this solution depends on how complicated the search condition is.

Hope this help.

Dinh Cong Bang.


In article <7um7aj$c86$1_at_nnrp1.deja.com>,   Sue Han <sue_han_at_my-deja.com> wrote:
> Hi,
>
> How can I know how many rows will be returned from the query
>
> SELECT *
> FROM table1 t1, table2 t2
> where t1.column1 = t2.cloumn2;
>
> I know it can be done by
>
> SELECT count(*)
> FROM table1 t1, table2 t2
> where t1.column1 = t2.cloumn2;
>
> But I don't want to touch the actual data to get the information. Is
> there any statistics about that, and where is it stored? How can I get
> it by program?
>
> I am wondering how the optimizer works it out.
>
> Thanks in advance.
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Thu Oct 21 1999 - 12:27:10 CEST

Original text of this message