dbs[i] = useDefaultBag ? BagFactory.getInstance().newDefaultBag()
// In a very rare case if there is a POStream after this
// POJoinPackage in the pipeline and is also blocking the pipeline;
// constructor argument should be 2 * numInputs. But for one obscure
// case we don't want to pay the penalty all the time.
: new InternalCachedBag(numInputs-1);
}
// For last bag, we always use NonSpillableBag.
dbs[lastBagIndex] = new NonSpillableDataBag((int)chunkSize);
//For each Nullable tuple in the input, put it