Re: Check constraints on non-immutable keys - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Check constraints on non-immutable keys
Date
Msg-id 19277.1277938670@sss.pgh.pa.us
Whole thread Raw
In response to Re: Check constraints on non-immutable keys  (Peter Eisentraut <peter_e@gmx.net>)
Responses Re: Check constraints on non-immutable keys  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Peter Eisentraut <peter_e@gmx.net> writes:
> <kibo>
> "The <search condition> shall simply contain a <boolean value
> expression> that is retrospectively deterministic."

> This is then defined in a rather complex manner that ends up disallowing
> col > now() but allowing col < now().
> </kibo>

Oh, cute.  Seems to have been added in SQL:2003.  I guess somebody
nagged them about wanting to be able to write CHECK(col <= now()).
The detailed definition is amazingly laborious and yet limited, though,
as it basically doesn't address the problem except for that specific
case and close relatives.
        regards, tom lane


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