Tip 2: Updating Big Content Farms

This
tip is for Windows SharePoint Services 3.0 and Microsoft Office SharePoint
Server 2007 and may apply to SharePoint Foundation 2010 and SharePoint Server 2010.

If
your SharePoint farm has a large amount of content then detaching the content
databases from the web applications before running the SharePoint Products and
Technologies Configuration Wizard on the first server in the farm will speed up the installation
and upgrade wizard. Of course you will still have to reconnect
the databases afterward, but if you are doing the upgrade after hours at least
you can get through the manual part of the install and monitor the attach
process.

*One
caveat, when you detach a content database, the next crawl of the site
collections in that database will be full even if they are scheduled as
incremental.