SQL Server 2005 XML Methods, Part Four, The Existential Quandary

We've seen SQL Server 2005 XML data retrieval methods in previous posts. In particular we've seen how they perform compared to T-SQL retrieval methods, and – quite frankly – the results were somewhat disappointing. There is an XML retrieval method that we haven't discussed yet. There are two reasons why not: It's not really a retrieval method as much as it is a way of testing whether