db.housingPrice.ensureIndex({sHotelId:1},{name:'sHotelId_'},{background:true});
db.housingPrice.ensureIndex({sRoomId:1},{name:'sRoomId_'},{background:true});
db.housingPrice.ensureIndex({sRoomId:1,userName:1},{name:'sRoomId_userName'},{background:true});