In Memory Caching of Dataset

I am planning to do some in memory caching of my data for operations in my web service. This data would be basically lookup values which do not change frequently. I was planning 开发者_运维问答to get all that data in datasets (multiple tables) and store them till the data does not change on DB side. This is so because some of my data never changes, where some may change quite frequently. Any idea?

I would probably cache it at the DataTable level, then each table could have it's own caching rules (expiration time, last updated, etc, etc).