Re: Ensureing 1to1 relation with multiple Key Fields

From: damorgan <dan.morgan_at_ci.seattle.wa.us>
Date: Mon, 04 Feb 2002 18:10:15 GMT
Message-ID: <3C5ECE87.A9E55E32@ci.seattle.wa.us>

By SQL only do you mean no PL/SQL? Because this could be easily done with NOT EXISTS. Daniel Morgan

Simon Klaiber wrote:

> Hi,
>
> I have following problem:
>
> I have two tables with about 10 million data sets each. Every Dataset
> is indentified by a unique (per table) combination of the datafields
> (lets call them c1, c2 and c3).
>
> I need to find a SQL only Solution to filter out all all datasets that
> don't have a matching (same c1, c2 and c3) dataset in the other table.
>
> Looking at the big amount of Datasets it must be done in a perfomant
> way.
>
> Do you havb a tip how to try it?
>
> Thanks
> Simon
> Frankfurt/Germany
Received on Mon Feb 04 2002 - 12:10:15 CST