// Build Map with evaluated hash key as key and row as value
for (int i = 0; i < nRows; i++) {
int resultSize = (int)Bytes.readVLong(hashCacheByteArray, offset);
offset += WritableUtils.decodeVIntSize(hashCacheByteArray[offset]);
ImmutableBytesWritable value = new ImmutableBytesWritable(hashCacheByteArray,offset,resultSize);
Tuple result = new ResultTuple(new Result(value));
ImmutableBytesPtr key = TupleUtil.getConcatenatedValue(result, onExpressions);
List<Tuple> tuples = hashCacheMap.get(key);
if (tuples == null) {
tuples = new ArrayList<Tuple>(1);
hashCacheMap.put(key, tuples);