Thanks Gustaf, I just updated my CR to remove those LOCK TABLE statements and wanted to report that it made a significant improvement to the assessment page load times when posting a page full of questions. Also copying a large assessment with hundreds of content items is MUCH faster now.
So I'd encorage anyone who with a newer version of Postgres to make sure those LOCK TABLE statements are not being used. Look in acs-content-repository/tcl/content-item-procs.tcl and content-revision-procs.tcl.
