Mike,

I like the idea of indexes in xml datatypes, particularly when combined with schemas.  There was a comment in one of Steve’s editorial posts a few weeks ago that said something like “let databases do what they are good at – rows and columns” – this makes sense but a small feature such as indexes on xml raises the question “well what if SQL databases were good at xml too?”  I don’t know much about the internals of the database engine but I imagine that if the xml indexes were handled in the same way as ‘normal’ indexes that you could get similar performance – regardless of whether your index is on a field or an xml attribute.  So, if the query plan for a field looks the same as a query plan for xml, using index seeks, then surely we could argue that SQL databases are becoming good at handling not just rows and columns, but xml too?

My current implementations are tentative seductions by the xml temptress and although it appears that indexes on xml data do work, I haven’t taken the time yet to perform some real tests.

Simon