There is an Oracle whitepaper comparing RAC (wonderful, performant and simple) with SQL Server 2008 (awful, slow and complex :)) In it there is an interesting table for ERP schemas. Now I know some of apps predates declarative referential integrity, but that was introduced an awfully long time ago now. Tables Primary Key Indexes Peoplesoft 7,493 6,438 Oracle eBusiness (ERP) 8,155 800 SAP 16,500 16,329 -- Niall Litchfield Oracle DBA http://www.orawin.info