if(_type!=AggType.PARTITION) {
_stream = _globalScheme.aggPartition(_stream);
BatchToPartition singleEmit = _globalScheme.singleEmitPartitioner();
Aggregator toAgg = combined;
if(singleEmit!=null) {
toAgg = new SingleEmitAggregator(combined, singleEmit);
}
// this assumes that inFields and outFields are the same for combineragg
// assumption also made above
_stream = _stream.partitionAggregate(inFields, toAgg, outFields);
}