EDIT

One problem that arises is the correct use of numbers in Java, Hibernate + DB. For correct rounding etc. we should better use BigDecimal rather than Double.

However, BigDecimal is stored as Numeric(PRECISION,SCALE) with a fixed SCALE value. To allow different Scaling per record we may want to implement a BigDecimalUserType. This can be found at https://bitbucket.org/ratkins/bigdecimalusertype/.

http://stackoverflow.com/questions/6544232/how-do-i-map-a-bigdecimal-in-hibernate-so-i-get-back-the-same-scale-i-put-in

Alternatively we may use UserType with String representation !! But this may not allow Database computations on values.

https://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html

first implementations but commented r22246