Float Infinity

Hi All,

I just want to ask shouldn't substraction from infinity returns infinity
in float just like in timestamp?

This is for float:

a=# SELECT version();
version
------------------------------------------------------------------------------------------------
PostgreSQL 8.1.5 on i386-portbld-freebsd6.2, compiled by GCC cc (GCC)
3.4.6 [FreeBSD] 20060305
(1 row)

a=# SELECT 'Infinity'::float;
float8
----------
Infinity
(1 row)

a=# SELECT 'Infinity'::float-10;
ERROR: type "double precision" value out of range: overflow
a=# SELECT 'Infinity'::float+10;
ERROR: type "double precision" value out of range: overflow
a=# SELECT 'Infinity'::float-10::float;
ERROR: type "double precision" value out of range: overflow
a=# SELECT 'Infinity'::float+10::float;
ERROR: type "double precision" value out of range: overflow

And this is for timestamp:

a=# SELECT 'Infinity'::timestamp;
timestamp
-----------
infinity
(1 row)

a=# SELECT 'Infinity'::timestamp-'10 days'::interval;;
?column?
----------
infinity
(1 row)

Regards,
Kaloyan