Thanks to comments from TeeJay and perrin, I've rewritten my database modules to use set_sql. This has improved the performance of my application plus it's given me the greater flexibility that I require (using SQL::Abstract [cpan.org]). As TeeJay suggested I followed Randal's Example [class-dbi.com].
I now see how I can integrate Class::DBI and SQL::Abstract into my day jobs application but I'm vacation from that for 2 weeks so that train of thought will have to wait.
