title: Small database system as ACL for ASP.NET site
body: <p>I have a web based ASP.net platform which serves many thousands of clients per day. Roughly 100 connections per minute. This could increase by 10x potentially.</p>
  
  <p>When the clients connect to the system I can identify them uniquely, and I need a simple database which can be queried for 2 things:
  1) Is this ID valid?
  2) How many IDs are in the database total?</p>
  
  <p>If the ID is not valid, I would ordinarily add it to the database upon first seeing the ID.</p>
  
  <p>I have tried Microsoft SQL CE - but I am now seeing issues with too many sessions. I would like to avoid a dedicated SQL system (SQL Server Express etc) and stick to a more "embedded" option.</p>
  
  <p>What systems would you guys recommend?</p>