I am about to go through the process of upgrading my SQL Server 2005 to 2008. Running the Upgrade Advisor indicated that I had a global trace flag (8017), and that this needs to be disabled in order to run the upgrade, and can then be re-enabled afterwards.

Turning the flag off is simple enough (DBCC TRACEOFF(8017, -1)). The question is, once i've upgraded do I actually need to turn it back on again? Is this something that Recorder needs or is it something that SQL Server 2005 thought it needed, but may now be redundant?