User-defined functions (UDFs) in SQL Server 2000 make reusing logic easy and help simplify complicated SQL statements. But do UDFs have any hidden performance costs?

I use UDFs regularly, and if you use them properly, they're efficient and effective. However, as with other SQL Server solutions, you need to be aware of the performance implications of using UDFs. And to understand those implications, you need to know how SQL Server handles T-SQL.

You...