On 11 June 2011 14:40, Thom Brown <t...@linux.com> wrote: > On 11 June 2011 14:32, Dean Rasheed <dean.a.rash...@gmail.com> wrote: >> On 1 June 2011 23:47, Alvaro Herrera <alvhe...@commandprompt.com> wrote: >>> >>> Here's a complete patch with all this stuff, plus doc additions and >>> simple regression tests for the new ALTER DOMAIN commands. >>> >>> Enable CHECK constraints to be declared NOT VALID >>> >>> This means that they can initially be added to a large existing table >>> without checking its initial contents, but new tuples must comply to >>> them; a separate pass invoked by ALTER TABLE / VALIDATE can verify >>> existing data and ensure it complies with the constraint, at which point >>> it is marked validated and becomes a normal part of the table ecosystem. >>> >> >> I think that you also need to update the constraint exclusion code >> (get_relation_constraints() or nearby), otherwise the planner might >> exclude a relation on the basis of a CHECK constraint that is not >> currently VALID. > > Do the standards explicitly stipulate an expected behaviour for this?
No I believe that this is a PostgreSQL-specific optimisation, and we need to ensure that queries return the correct results with constraint_exclusion on. > And does such a problem affect the invalid foreign key change too? No only CHECK constraints (and possibly NOT NULL constraints in the future). Regards, Dean -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
