I have completed the open issues (that I'm aware of) for operator exclusion constraints:
http://archives.postgresql.org/message-id/1257101600.27737.159.ca...@jdavis I'd now like to propose an extension to that feature: cardinality limits. It could go something like this (syntax still open for discussion, for illustration only): EXCLUSION (room CHECK WITH =, attendee CHECK WITH =, during CHECK WITH &&) CARDINALITY 30 To mean that at most 30 attendees can be signed up for the same room at overlapping times. I have hacked up a basic prototype just to make sure the semantics can work reasonably well. I haven't implemented the syntax or catalog changes yet, but the basic semantics with a hard-coded cardinality seem to hold up. Thoughts? Regards, Jeff Davis -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
