I've seen database profiling numbers from some of my clients, but obviously I can't publish those. To be clear all I'm claiming is that for most webapps the overwhelming majority of database queries are simple indexed column lookups, not that most webapps are putting document blobs in the database or using EAV style or anything like that.
Well, "key-value store" means different things to different people. If most queries are simple indexed column lookups then that carries my original point: query parse time is actually a significant proportion of overall datastore request processing time.
