You are designing a web service that will be hosted in Windows Azure. 
The web service will accept and store structured and semi-structured data. The web service must meet the following requirements：  
- Update all data within a single transaction. 
- Enforce the data structure for structured data within the data store.   
You need to recommend an approach for storing the data. 
What should you recommend？（）

You are designing a Windows Azure application that will store data. You have the following requirements：  
- The data storage system must support the storage of more than 500 GB of data.  
- Data retrieval must be possible from a large number of parallel threads without threads blocking each other.  
You need to recommend an approach for storing data. 
What should you recommend？（）