@Override
public void merge(FunctionContext ctx, Tuple part) {
AvgContext avgCtx = (AvgContext) ctx;
ArrayDatum array = (ArrayDatum) part.get(0);
avgCtx.sum += array.get(0).asDouble();
avgCtx.count += array.get(1).asLong();
}
@Override
public Datum getPartialResult(FunctionContext ctx) {
AvgContext avgCtx = (AvgContext) ctx;
ArrayDatum part = new ArrayDatum(2);
part.put(0, DatumFactory.createDouble(avgCtx.sum));
part.put(1, DatumFactory.createLong(avgCtx.count));
return part;
}