A common question I receive is that the production database gets bigger and bigger when duing SiteDeployment imports although items are only updated and no new items are added.
The reason for this is that during import a new historical revision will be created for all updated items. If you have frequent update this can cause a significant grow for the database. To reduce this it is required to clear the revision history on the production system.
Unfortuantelly this can only be done using Site Manager and not using script. So it is required to have at least one read-write web site on a MCMS server that is connected to the production database to allow Site Manager to connect to the server to clear the revision history.
If this has never been done before clearing the revision history can be a very time consuming job that can take several hours. In addition the MCMS server doing this job is running on high CPU till the revision history has been cleared. To address this Microsoft created an KB article with instructions on how to replace the stored procedure responsible for clearing the revision history with a more efficient version: