I'm writing a simple program in C# which stores some data and then use simple queries to generate reports, ... .

the data are about **a million** records. 

what's an efficient way to do this? should I use MsSql, MySql, ..., or there is a easier way to manage and use this amount of data?

**UPDATE:** actually by *efficient* I meant *simple*. I want my program to standalone if possible. using simple files for storing data, etc. but I don't want to create everything from scratch.

tnx