Meaning of TYPE_NAME in type_info() output

If I make a user-defined type synonym, should the name of this synonym
appear as TYPE_NAME in the type_info() output or should TYPE_NAME give
the original SQL type the synonym is defined as?

Currently if I make a user-defined type on Sybase and use it for some
column C of a table T, then for 'SELECT C FROM T' DBD::Sybase gives me
the name of the user type.  I think I would prefer it to give the
original SQL like 'varchar(10)' in the TYPE_NAME field, but I don't know
what other DBDs do.

What is the intended behaviour of TYPE_NAME in this case?  I'm sure
other RDBMSes allow user-defined type synonyms.

I think it would be best to resolve the synonym down to plain SQL type
name if possible - but if that isn't possible (eg it really is a user-
defined type, not just a synonym) then leave the name.

-- 
Ed Avis <[email protected]>