This has been asked before many times but i couldnt find a conclusive answer to this. Can anyone assist

I want to be able to query my database (will my sqlServer AND mysql) using nhibernate in order to get X number of rows. these numbers need to be unique. I am selecting 250 out of 350 so my odds are high that i will have duplicates (because random doent imply unique)

This needs to work for both mysql and sql server.

since I am selecting over 70% of the table already, i dont mind selecting all the records, and using LINQ to pul out the 250 unique values (if this is possible)

whatever has the least impact on my system overhead.

Thanks!