Re: Cached plans and statement generalization

>
> A naive option would be to invalidate anything that depends on table or
> view *.FOOBAR. You could probably make it a bit smarter by also requiring
> that schema A appear in the path.
>

This has been rumbling around in my head. I wonder if you could solve this
problem by registering dependencies on objects which don't yet exist.
Consider:

CREATE TABLE C.T1(...);
CREATE TABLE C.T2(...);
SET search_path='A,B,C,D';
SELECT * FROM C.T1, T2;

For T1, you'd register a hard dependency on C.T1 and no virtual
dependencies since the table is explicitly qualified.

For T2, you'd register a hard dependency on C.T2 since that is the table
that was selected for the query. You'd also register virtual dependencies
on A.T2 and B.T2 since if either of those tables (or views) are created you
need to recompile the statement. (Note that no virtual dependency is
created on D.T2() since that table would never be selected by the compiler.)

The catch is that virtual dependencies would have to be recorded and
searched as strings, not OIDs since the objects don't exist. Virtual
dependencies only have to be checked during CREATE processing though, so
that might not be too bad.

But this is getting off topic - I just wanted to capture the idea while it
was rumbling around.