UNION docs

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От Bruce Momjian
Тема UNION docs
Дата
Msg-id 199903190221.VAA13530@candle.pha.pa.us
обсуждение исходный текст
Список 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
operandsof 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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