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Re: Execute query with EXCEPT, INTERSECT as anti-join, join?

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Colin 't Hart" <colinthart@gmail.com>
Cc: PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2013-11-11T13:34:43Z
Lists: pgsql-hackers 
"Colin 't Hart" <colinthart@gmail.com> writes:
> I can't get Postgresql to execute a query with EXCEPT (or INTERSECT)
> as an anti-join (or join).

> Is this even possible?

No, and it probably won't ever be, since the semantics aren't the same.
EXCEPT/INTERSECT imply duplicate elimination.

			regards, tom lane