Few new articles about NAV on SQL released by experts:
Lars Lohndorf-Larsen article "Record-level locking in the SQL Server option for Microsoft Dynamics NAV"
Waldo BLOG "What impact does my C/AL have on SQL?"
And look to Jörg A. Stryk homepage for ideas and help.
Also can look at:
www.microsoft.com/.../Case_Study_Detail.aspx