Why do you think so? This makes perfect sense to me - imperative language wraps purely functional one, and sits on top of declarative, relational language(s)[1]

Why do you think so? This makes perfect sense to me - imperative language wraps purely functional one, and sits on top of declarative, relational language(s)[1] for data storage and manipulation. The GP is using a very well thought out configuration; this is using the right tool for the job incarnate. If I wasn't lacking in SQL department I would probably do exactly the same (probably replacing PHP with something strongly and maybe statically typed). [1] SQL and XML seems a bit redundant, but I don't know what they are used for exactly. Also I lumped both SQL and XML together as "relational" because of XQuery, but I admit that I don't know much about the latter and this may be not accurate.