SQL Server 2005缓存依赖性 - 是否有限制。注册表？

I'm trying to implement sql server 2005 cache dependency in ASP.Net 3.5. I have a lot of lookup tables (around 50 in all) in my database that will hardly change after the initial setup. I plan to register all of them in the SQLCacheDependency. I'm wondering if there will be a performance hit when so many tables are registered, because SQL Server will need to keep track of when their data change. And will these overheads nullify the benefits of caching in the first place? Thank you very much.I'm trying to implement sql server 2005 cache d