Major Description
This patch should improve comparison performance on TupleWritables. It saves the deserialization overhead. It is particularly useful when the input tuple are large, e.g. contains long strings.
Please note that this changes the binary format of TupleWritable. It adds a var-int indicating size of field after each type code. This is a limitation of the writable system. We do not know the size of each field until fully desalinizing it.