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From: steve@violet.berkeley.edu (Steve Goldfield)
Newsgroups: comp.databases
Subject: Ingres Question: Duplicate Rows
Message-ID: <1990Aug8.230913.2897@agate.berkeley.edu>
Date: 8 Aug 90 23:09:13 GMT
Sender: usenet@agate.berkeley.edu (USENET Administrator;;;;ZU44)
Reply-To: steve@violet.berkeley.edu (Steve Goldfield)
Organization: University of California, Berkeley
Lines: 25

I've just been debugging a discrepancy between two reports.
In one report, the table it drew from had enough columns to
have all rows unique. In the other report, I only took a few
columns because I was just looking for cumulative totals. I
found the discrepancy caused by Ingres' suppression of
duplicate rows.

The Ingres/Quel reference manual (we are using Release 5.0)
says that duplicate rows are not allowed except in a heap
structure. The table in question was a heap, but duplicates
appear to have been suppressed anyway.

Does anyone know whether the unwanted suppression of duplicate
rows is a bug or a feature? If it is a feature, it seems
an undesireable one to me, since I can think of lots of
situations where I would like to allow the possibility of
duplicate rows. It seems bothersome to have to include an
unwanted column in a table just to keep the rows unique.

Any comments? Is there (should there be) a user flag to
either turn on or turn off duplicate permission?

Steve Goldfield
College of Engineering
UC Berkeley