The query processor ran out of internal resources and could not produce a query plan. This is a rare event and only expected for extremely complex queries or queries that reference a very large number of tables or partitions. Please simplify the query. If you believe you have received this message in error, contact Customer Support Services for more information.

When I got this error, it took me a while to understand just what was wrong, and then I walked away, knowing that I'm smarter than SQL Server. :-)