使用WCF安全地让许多并发用户安全地访问MS-Access或Sqlite或其他基于文件的数据库？

I want to write a data access layer for a file based database behind a data driven website. There would be lots of concurrent update and reads going on, I'd like at the very least that access be serialized, so that page request would get in a nice orderly line.I want to write a data access layer for a file