> I see two different functions linked to from each pg_wchar_table
> entry... although perhaps those are associated with encodings
> not with conversions.
Yes. those are not directly associated with conversions.
> IIRC the existing conversion functions deal in C string pointers and
> lengths. I'm a little worried about the extra overhead implicit
> in converting to a TEXT object and back again; that probably means at
> least two more palloc and memcpy operations. I think you'd be better
> off sticking to a C-level API, because I really don't believe that
> anyone is going to code conversion functions in (say) plpgsql.
I am worried about that too. But if we stick a C-level API, how can we
define the argument data type suitable for C string? I don't see such
data types. Maybe you are suggesting that we should not use CREATE
FUNCTION?
--
Tatsuo Ishii