This adds a sql function, "BIG_SUM", that uses
CompressedBigDecimal to do a sum. Other misc changes:
1. handle NumberFormatExceptions when parsing a string (default to set
to 0, configurable in agg factory to be strict and throw on error)
2. format pom file (whitespace) + add dependency
3. scaleUp -> scale and always require scale as a parameter
Compressed Big Decimal is an extension which provides support for
Mutable big decimal value that can be used to accumulate values
without losing precision or reallocating memory. This type helps in
absolute precision arithmetic on large numbers in applications,
where greater level of accuracy is required, such as financial
applications, currency based transactions. This helps avoid rounding
issues where in potentially large amount of money can be lost.
Accumulation requires that the two numbers have the same scale,
but does not require that they are of the same size. If the value
being accumulated has a larger underlying array than this value
(the result), then the higher order bits are dropped, similar to what
happens when adding a long to an int and storing the result in an
int. A compressed big decimal that holds its data with an embedded
array.
Compressed big decimal is an absolute number based complex type
based on big decimal in Java. This supports all the functionalities
supported by Java Big Decimal. Java Big Decimal is not mutable in
order to avoid big garbage collection issues. Compressed big decimal
is needed to mutate the value in the accumulator.
Frank Chen
Sam Rash
senthilkv