Current indexes on [sys_schema_change] does not seem to be able to handle a large number of records, and can cause page to not load

1. Get [sys_schema_change] table to be large, mil+ for good measure
2. Upgrade an instance so that the upgrad monitor page has stats from the upgrade to display
3. Nav to upgrade monitor $upgrade_client.do
   
   Page takes several minutes to load or can have the maximum execution time exceeded and not load.

Add the following index to speed things up: sys_schema_change(started, finished, duration)