ds.setPartitions(collectionPartitions);
}
RecordDescriptor rDesc = new RecordDescriptor(new ISerializerDeserializer[opSchema.getSize()]);
IOperatorDescriptor scanner = new VXQueryCollectionOperatorDescriptor(jobSpec, ds, rDesc);
AlgebricksPartitionConstraint constraint = getClusterLocations(nodeList, ds.getPartitionCount());
return new Pair<IOperatorDescriptor, AlgebricksPartitionConstraint>(scanner, constraint);
}