I need to do the following thing:

var a = from c in DB.Customers where (from t1 in DB.Table1 where t1.Date >= DataTime.Now select t1.ID).Contains(c.ID) && (from t2 in DB.Table2 where t2.Date >= DataTime.Now select t2.ID).Contains(c.ID) select a

It doesn't want to run. I get the following error:

Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

But when I try to run

var a = from c in DB.Customers where (from t1 in DB.Table1 where t1.Date >= DataTime.Now select t1.ID).Contains(c.ID) select a

OR

var a = from c in DB.Customers where (from t2 in DB.Table2 where t2.Date >= DataTime.Now select t2.ID).Contains(c.ID) select a

It works!

I'm sure that there both IN queries contain some customers ids.