Re: Re-create dependent views on ALTER TABLE ALTER COLUMN ... TYPE?

* Robert Haas (robertmhaas@gmail.com) wrote:
> On Mon, Jun 2, 2014 at 10:21 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> > The real problem in my mind is one of user expectations.  If the database
> > silently does something behind your back, people expect that that action
> > will be *right* and they don't have to worry about it.  I don't think
> > that automatically reparsing views has much chance of clearing that bar.
[...]
> >From a technical standpoint, I'm not very sure what to do to further
> improve the situation - which I will broadly characterize as "view
> dependency hell" - but if I did have such an idea I might be willing
> to take a modest risk of user confusion if it seemed likely to also
> reduce user frustration.

Tom's point goes back to what I was trying to drive at originally-
people should have to ask for this.  Perhaps we can provide a way for
them to ask which is explicit enough that they understand "this might
not do exactly what you think it does", akin to what happens today with
a drop-and-recreate-everything approach.  'CASCADE' might not be
sufficient to meet that, maybe 'CASCADE REBUILD' or something?

Of course, there is a question about if it's worth it to keep around the
exact text of each CREATE VIEW and build all this infrastructure for
something which will only work properly in a specific subset of cases
and in many others could break silently, essentially installing a very
handy looking foot-gun.  Not sure I like that either.
Thanks,
    Stephen