On Wed, Nov 07, 2012 at 05:55:32PM -0500, Tom Lane wrote: > David Fetter <da...@fetter.org> writes: > > On Wed, Nov 07, 2012 at 05:04:48PM -0500, Tom Lane wrote: > >> Should we be doing something > >> about such cases, or is playing dumb correct? > > > The SQL standard handles deciding the behavior based on whether WITH > > CHECK OPTION is included in the view DDL. See the section 2 of the > > SQL standard (Foundation) for details. > > Ah, I see it. So as long as we don't support WITH CHECK OPTION, we > can ignore the issue.
I don't think it's as simple as all that. WITH CHECK OPTION is how the SQL standard allows for creating update-able views in the first place, so we want to be at least aware of what the standard mandates. Here's what I'm able to apprehend from the standard. There are three different WITH CHECK OPTION options: WITH CHECK OPTION WITH CASCADED CHECK OPTION WITH LOCAL CHECK OPTION - WITH CHECK OPTION means that the results of INSERTs and UPDATEs on the view must be consistent with the view definition, i.e. INSERTs any of whose rows would be outside the view or UPDATEs which would push a row a row out of the view are disallowed. - WITH CASCADED CHECK OPTION is like the above, but stricter in that they ensure by checking views which depend on the view where the write operation is happening. INSERTs and UPDATEs have to "stay in the lines" for those dependent views. - WITH LOCAL CHECK OPTION allows INSERTs or UPDATEs that violate the view definition so long as they comply with the WITH CHECK OPTION on any dependent views. Apparently the LOCAL here means, "delegate any CHECK OPTION checking to the dependent view, i.e. check it only locally and not right here." Oh, and I'm guessing at least one well-known financial services company would just love to have these :) Cheers, David. -- David Fetter <da...@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fet...@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
