Re: Problem with union in Oracle 7.3

From: Pavel Polcar <pavel.polcar_at_berit.cz>
Date: 1998/01/23
Message-ID: <01bd281a$ef301b50$504331c3@polcar_nt4002>#1/1

Hi,
try using UNION ALL instead of UNION. UNION attempts to remove duplicates from the resulting set which takes time for larger table.

Regards

Pavel

Hein van Vroonhoven <Hein.vanVroonhoven_at_ahm.akzonobel.nl> wrote in article <01bd2800$7bcbb260$5310030a_at_AHM01395.ahm-nl.akzonobel.nl>...
> We have two personell tables with a number of equal columns.
> I have made views on each of these tables.
>
> I have to union these views to make some reports. Therefore I made a new
> view.
> When I use the separate tables in the reports there is no problem. But
when
> I use the view with the union, the performance decreases dramatically.
>
> I can't merge the two tables. But can anyone help me bypassing this
> problem.
> Is there a way to use the two tables in one SQL statement, but not using
> the UNION operator.
>
> Thanks in Advance.
>
> Hein v. Vroonhoven (Hein.vanVroonhoven_at_AHM.akzonobel.nl)
>
>
Received on Fri Jan 23 1998 - 00:00:00 CST