>>-RAND--(--+------------+---)---------------------------------><
'-expression-'
The schema is SYSFUN.
Returns a random floating point value between 0 and 1 using the argument as the optional seed value.
An argument is not required, but if it is specified it can be either INTEGER or SMALLINT.
The result of the function is a double-precision floating-point number. The result can be null; if the argument is null, the result is the null value.