Is there an explanation of these statuses anywhere?
http://dev.mysql.com/tech-resources/articles/using-new-query-profiler.html
my specific question is in reg
http://dev.mysql.com/doc/refman/5.0/en/general-thread-states.html
Executing means the thread has started execution, Sending data apparently covers both the processing of the rows and sending the count back to the client.