Affects Version/s: 3.12.0, 4.0.0
Fix Version/s: None
It has been spotted by many clients that the floating point handling in Impala / HUE can differ, and resulting in rounding differences. This is a problem for financial customers where the analysts can see a different value running through HUE than the ones provided in impala-shell or through JDBC for example.
Attached please find a small set of sample data that shows how the representation differs for the double data type, that people would like to use mostly.
These are simply showing the rounding differences for double, but customers would like to see these to be consistent across the tools:
select "double",cast("8.831" as double);
select "decimal",cast("8.831" as decimal(5,3)) ;
select "float",cast("8.831" as float);
This particular action shows how due to type unification even the decimal(x,y) value can be distorted and differ.
select "double",cast("8.831" as double)
select "decimal",cast("8.831" as decimal(5,3))
select "float",cast("8.831" as float)