Re: Cache lookup errors with functions manipulation object addresses

Álvaro, all,

On Fri, Dec 14, 2018 at 09:04:36AM +0900, Michael Paquier wrote:
> Thanks again for looking up at what was proposed. I'll see if I can
> finish the refactoring part for the next CF, and be done with this
> stuff.

Please find attached an updated patch set which reworks the SQL
interface for object addresses so as NULL-ness is handled consistently
for all object types. This has needed a couple of extensions to some
current object-lookup APIs, which are added as refactoring bits
without breaking existing callers:
- Procedures and operators gain a new _extended routine which can take
a set of flags to enforce a NULL result or force qualification.
- format_type_extended needs an extra flag to enforce NULL.

On top of the refactoring issues, here is the list of changes to make
things work:
- The object type can never be NULL, meaning that for undefined
relations, routines or constraints the caller gets a generic name even
if the object is not defined. (That's the definition mentioned a
couple of messages upthread).
- Large object existence is checked with LargeObjectExists().
- Table columns show all the fields as NULL if the object identity
cannot be found instead of showing the table and its schema.

With that all the regression tests show a consistent behavior for all
object types when those are undefined. Thoughts?
--
Michael