On sön, 2011-03-06 at 12:16 -0500, Tom Lane wrote:
> I'm still not thrilled with the plan of sprinkling the code with
> random fmgr_info_collation() calls to make up for the lack of a sane
> default. IMO, that *is* a default, just a badly implemented one.
We have touched upon this point several times during the development of
this patch. The main problem is that you need to distinguish no
collation from the default collation, so they can't both be OID zero.
Another problem is that if you assume OID zero means default, finding
bugs in the expression tree analysis would be really hard. It would be
like saying, oh, we have type OID zero, let's make it text and proceed.