How to test query execution time

I was going to create a whole bunch of random data for my tables, and start playing around with indexes and so forth to start getting a grip on tuning.

Is there any way to properly test the *time* a particular query takes? Meaning, is there a way to tell Oracle to disable all caches and whatnot (I don't know every single thing that I'd need to disable), so that if I run a query 10 times, it'll take about the same time every time?

It would be nice if it's possible to make changes to indexes, etc, as I go, and run the query with confidence that my changes have really made the query run more quickly, instead of just Oracle fetching the data quickly out of some cache.

I've been searching for documentation, but can't find anything so far. Yes, it's obvious I'm a newbie at tuning, so don't assume I know much, because I obviously don't!

I'm aware of EXPLAIN PLAN which shows the execution path, but that doesn't have much to do with the time. Received on Fri Jun 28 2002 - 21:54:56 CDT