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From: setas01@cai.com
Newsgroups: comp.databases
Subject: Re: Union and Views
Message-ID: <326.26caf0f0@cai.com>
Date: 16 Aug 90 19:16:00 GMT
Organization: Computer Associates International
Lines: 28

Subject: Union and Views

Aaron Watters (aaron@grad2.cis.upenn.edu) from University of Pennsylvania
writes :

> I recently volunteered some consulting for a friend
> about a difficult database problem.  The solution we came
> up with was unduely complex because of the following
> weird restriction:

> In Informix, for example, Unions are not allowed in the
> definitions of Views.  Why is this?

What reason did Informix give for not supporting this feature ?

> Do other systems have this restriction?

It would be interesting to know if others also have this restriction.
CA-DB ( a relational database software on VAX/VMS and UNIX ) does not 
have this restriction. 

> How can system implementers look themselves in the mirror when
> they impose such arbitrary restrictions on their customers?

Let us see what the implementors have to say on this.


Ashok Sethi