Asset Collection:
1. _id_
2. CategoryId_1_Date_-1
3. CategoryId_1_Id_1
4. CategoryId_1_Name_1
5. CategoryId_1_Weight_1
6. GroupId_1
7. Name_1
Category Collection:
1. _id_
2. Name_1
Payload Collection:
1. _id_
2. AssetIds_1
原文：http://www.cnblogs.com/AllanDragoon/p/4047731.html