Re: Interesting SQL that displays time taken to do row count?

Basically you can't. You are on the wrong track. Also you seem to be tracking information that is already being maintained in v$sql. But if you insist: you really need to
get_time
run query
get_time
and/or generate level 12 trace files
or better still, buy something like Quest Central and don't waste your time on reinventing the wheel.

-- 
Sybrand Bakker
Senior Oracle DBA