Implemented special case code for grouping  1 and 2 byte wide values.
Implemented special case code for grouping  1 and 2 byte wide values.

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb