Hi Jean-Marc,

I was trying to profile updating expression, and the result is [XUST0001] prof:time(value[,cache[,label]]): no updating expression allowed. Is this a desired behavior ?

This is indeed the expected behavior. The reason is that updates will always be performed after the query itself has been evaluated, which is why the time for performing the update cannot be measured within XQuery. See [1] for more details. Best, Christian [1] http://docs.basex.org/wiki/XQuery_Update#Concepts