Float/Numeric?

Could anyone tell me why the following does not work without a cast?

mm=> select * from test;
f|i|a
------+-+---------------------
404.90|1|{0,1,2,3,4,5,6,7,8,9}
(1 row)

mm=> select i from test where f=404.90
mm-> ;
ERROR: Unable to identify an operator '=' for types 'numeric' and 'float8'
You will have to retype this query using an explicit cast
mm=> select i from test where f::float=404.90;
i
-
1
(1 row)

Shouldn't there be an implicit cast between numeric and float?

Michael
--
Michael Meskes | Go SF 49ers!
Th.-Heuss-Str. 61, D-41812 Erkelenz | Go Rhein Fire!
Tel.: (+49) 2431/72651 | Use Debian GNU/Linux!
Email: Michael(at)Fam-Meskes(dot)De | Use PostgreSQL!