Oracle FLOAT(126) can't handle +/-1.79E+308 to but MS/MySQL/Postgres can

Question

SQL Server, MySQL and Postgres can all have DOUBLE that is a 64bit floating point number holding the range -1.79E+308 to 1.79E+308. The Oracle docs say to use FLOAT(126) as DOUBLE, but it cannot handle this range, it only seems to cope somewhere around 1E+125
I've tested on both Oracle 10g and Oracle 10g Express.
How can I get the proper range for 64bit floating point numbers? What is the absolute maximum range an Oracle floating point number can handle? I've had the exact same issues with BINARY_DOUBLE not taking more than 1E+125
Lyle

Answer 1

Sub-Types
Here are the STANDARD sub-types defined in Oracle 10g (taken from the STANDARD package):
type NUMBER is NUMBER_BASE;
subtype FLOAT is NUMBER; -- NUMBER(126)
subtype REAL is FLOAT; -- FLOAT(63)
subtype "DOUBLE PRECISION" is FLOAT;
subtype INTEGER is NUMBER(38,0);
subtype INT is INTEGER;
subtype SMALLINT is NUMBER(38,0);
subtype DECIMAL is NUMBER(38,0);
subtype NUMERIC is DECIMAL;
subtype DEC is DECIMAL;
subtype BINARY_INTEGER is INTEGER range '-2147483647'..2147483647;
subtype NATURAL is BINARY_INTEGER range 0..2147483647;
subtype NATURALN is NATURAL not null;
subtype POSITIVE is BINARY_INTEGER range 1..2147483647;
subtype POSITIVEN is POSITIVE not null;
subtype SIGNTYPE is BINARY_INTEGER range '-1'..1;