On Tue, Aug 09, 2011 at 09:41:00PM +0200, Florian Pflug wrote: > Couldn't we simply give the user a way to specify, per column, whether or > not that column is a "KEY" column? Creating a foreign key constraint could > still implicitly mark all referenced columns as KEY columns, but columns > would no longer be "KEY" columns simply because they're part of a UNIQUE > constraint. Users would be free to add arbitrary columns to the set of > "KEY" columns by doing ALTER TABLE ALTER COLUMN SET KEY.
What would be the use case for manually expanding the set of key columns? If you have a heavily-updated table referenced by slowly-changing tables, it might pay off to disable the optimization entirely. That would be an esoteric escape hatch to provide for an uncommon use case, though. -- Noah Misch http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
