Property comparisons are defined on the Find methods and attach workflow scheduler task, and built into the SQL code that is used to query the database. Property comparisons require a complicated expansion of relationships. For example, if a find method is configured to search only for Current document versions, the method must build SQL to cross to the revision and only return those document versions that are set to Current.
To increase performance of this example, build this query around the document revision rather than the version, so it is looking at properties on the object queried for rather than on a related object. With related objects at several levels, choose the item with the most relations, in this case, the Master. For example, Classified Levels 1 to 3, which are relations from the Master, and owning group from the version. You can configure the method in several different ways, and take note on which database is most responsive.