SortRecordBatchBuilder containerBuilder = new SortRecordBatchBuilder(context.getAllocator(), MAX_SORT_BYTES);
for (CachedVectorContainer w : mmap.get(mapKey)) {
containerBuilder.add(w.get());
}
VectorContainer allSamplesContainer = new VectorContainer();
containerBuilder.build(context, allSamplesContainer);
List<Ordering> orderDefs = Lists.newArrayList();
int i = 0;
for (Ordering od : popConfig.getOrderings()) {
SchemaPath sp = SchemaPath.getSimplePath("f" + i++);