Oracle 9iR2 (9.2.0.7.0) on a Windows 2003 platform.

The Enterprise Manager's Index Tuning Wizard states in the header of
its reports:

=========
Index tuning analysis evaluates indexing strategies for schema
tables by processing collected SQL statements and other
evidence from a database application environment. The specific
goal is to recommend strategies that will effectively increase
performance for important application components.
==========

but what we cannot find any documentation on is what period of time the
analysis covers. One hour? 24 hours? Since the last instance
restart? Since instance installation?

This is an issue for us as we are currently in light-load testing of a
business software upgrade. We don't want to make changes that will
then be counterproductive when we go under heavy load. But if the
analysis is since instance restart or since instance installation, the
results might never be correct due to the long period of light-load
testing.

Input or pointers would be appreciated. Thanks.

sPh