Home -> Usenet -> comp.databases.theory -> Are there terms for these?

Are there terms for these?

From: Kenneth Downs <knode.wants.this_at_see.sigblock>
Date: Wed, 24 Aug 2005 17:48:08 -0400
Message-Id: <0g6vt2-inc.ln1_at_pluto.downsfam.net> 





Given two tables that are not UNION compatible, it seems there are ways to
UNION them anyway.



Method 1, Intersect their headers.  The resulting header is used to project
both tables and now those projections are union compatible.  What would
this be called?  I suppose if the intersected headers yield an empty set
nothing would happen here.



Method 2, Union their headers.  The resulting header is used to UNION both
tables, providing NULL or empty values where a column exists in one but not
the other.  What would this be called, a FULL OUTER UNION (ha ha)?



-- 
Kenneth Downs
Secure Data Software, Inc.
(Ken)nneth_at_(Sec)ure(Dat)a(.com)


Received on Wed Aug 24 2005 - 23:48:08 CEST












Original text of this message