"David G. Johnston" <david.g.johnston@gmail.com> writes:
> So I found where this difference in behavior is at least explicitly noted:
>/*
> * If it's a named composite type (or domain over one), find the typcache
> * entry and record the current tupdesc ID, so we can detect changes
> * (including drops). We don't currently support on-the-fly replacement
> * of non-composite types, else we might want to do this for them too.
> */
I'm not quite sure that that's related, really. That code is concerned
with detecting changes to an already-identified type (that is, type
OID NNN has different details now than it did before). It seemed to
me that Bryn's question was more about reacting to cases where a given
string of source code would resolve to a different type OID than it
did a moment ago. We don't have a great story on that, I'll agree.
You can get into that sort of problem without anywhere near the amount
of complexity embodied in this example --- for instance, I'm pretty
sure we don't re-parse type references just because somebody else
executed an ALTER TYPE RENAME somewhere.
regards, tom lane
