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UNION docs

From: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
To: lockhart(at)alumni(dot)caltech(dot)edu (Thomas G(dot) Lockhart)
Cc: docs(at)postgresql(dot)org (PostgreSQL-documentation)
Subject: UNION docs
Date: 1999-03-19 02:21:03
Message-ID: 199903190221.VAA13530@candle.pha.pa.us (view raw or flat)
Thread:
Lists: pgsql-docs
I't unnI don't understand this:

    The UNION operator specifies a table derived from a Cartesian product.
    The two tables that represent the direct operands of the UNION must
    have the same number of columns, and corresponding columns must be
    of compatible data types.</para>
    
Why do you call it a cartesian product.  I thought a cartesian product
was tableA x tableB, while UNION is really tableA + tableB, right?

If I am right, can you change the docs?  I will leave it as is.  Thanks.

-- 
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