Gevik Babakhani <pgdev@xs4all.nl> writes:
> I was wondering what the philosophy is behind letting an "ambiguous"
> function be created in the first place. Is this for backwards
> compatibility or perhaps for historical reasons?
Neither; it's a feature, and one we quite like. For example, would you
really prefer that the six different versions of abs() had to have
different names?
regression=# \df abs List of functions Schema | Name | Result data type | Argument data
types| Type
------------+------+------------------+---------------------+--------pg_catalog | abs | bigint | bigint
| normalpg_catalog | abs | double precision | double precision | normalpg_catalog | abs | integer
|integer | normalpg_catalog | abs | numeric | numeric | normalpg_catalog | abs |
real | real | normalpg_catalog | abs | smallint | smallint | normal
(6 rows)
Even if you were willing to do that, what about the forty-seven
distinct versions of "+"? Overloaded operators are not fundamentally
different from overloaded functions.
regards, tom lane