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Date: Fri, 8 Oct 2010 16:42:29 -0400
Message-ID: <AANLkTimRfzKH0DhyuMLpeU3g5GnCU6CuzYdxcph5HjqL@mail.gmail.com>
Subject: Re: Duplicates Processing
From: Gary Chambers <gwchamb@gmail.com>
To: Rob Sargent <robjsargent@gmail.com>
Cc: pgsql-sql@postgresql.org
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Rob,

> Perhaps a trade off between nullable fields and redundant types. =A0If
> your original table simply had a nullable column called
> isReplacementFor, into which you place in the subsequent rows the id of
> the first instance found.

Am I misunderstanding you when you're suggesting a table like:

part_number           INTEGER
is_replacement_for INTEGER references part_number
value                       INTEGER
wattage                   FLOAT8
...

-- Gary Chambers