Re: Mutable CHECK constraints? - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Mutable CHECK constraints?
Date
Msg-id 2189688.1674542289@sss.pgh.pa.us
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In response to Mutable CHECK constraints?  (Laurenz Albe <laurenz.albe@cybertec.at>)
Responses Re: Mutable CHECK constraints?
List pgsql-hackers
Laurenz Albe <laurenz.albe@cybertec.at> writes:
> We throw an error if the expression in a CREATE INDEX statement is not IMMUTABLE.
> But while the documentation notes that expressions in CHECK constraints are not
> to be immutable, we don't enforce that.  Why don't we call something like
> CheckMutability inside cookConstraint?  Sure, that wouldn't catch all abuse,
> but it would be better than nothing.

> There is of course the worry of breaking upgrade for unsafe constraints, but is
> there any other reason not to enforce immutability?

Yeah, that's exactly it, it's a historical exemption for compatibility
reasons.  There are discussions about this in the archives, if memory
serves ... but I'm too tired to go digging.

            regards, tom lane



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