Re: In UDAF, possible for terminatePartial to be called without init?

[Amareshwari Sri Ramadasu]

init() is called for all the aggregation evaluators, then terminatePartial() is 
called.

In your code, init() function is not overriding  GenericUDAFEvaluator.init(Mode 
m, ObjectInspector[] parameters). Hive calls GenericUDAFEvaluator.init.

Was the signature of the method wrong in your code?

Thanks
Amareshwari


On 2/15/11 10:23 PM, "Aurora Skarra-Gallagher" <aur...@yahoo-inc.com> wrote:

Hi,

I wrote a simple UDAF for Hive 0.6 and I had to include null checks in 
terminatePartial even though the object should never be null if init is always 
called before terminatePartial.

For instance, my init function:
        public void init() {
            result = new StringBuffer();
        }

My terminatePartial function:
        public String terminatePartial() {
            if (result == null) {
                return new String();
            }

            // Remove trailing comma, if string isn't blank
            if (result.length() > 0 && result.charAt(result.length() - 1) == 
',') {
                result.deleteCharAt(result.length() - 1);
            }

            return result.toString();
        }

If I don't have that initial null check, when the results are empty that I'm 
applying my UDAF to, I get a NullPointerException. It makes me think that 
terminatePartial can be called with no init call. Is that possible?

Thanks,
Aurora