If finding bugs in distributed applications feels more like luck than anything else, Casts Cast Application Mining Suite 4.0 may be something to try.
This source code and database schema analysis package provides impact analysis and code dependency reports, as well as a graphical display of how distributed components interact.
I used the software to analyze how pages in an ASP (Active Server Pages) application depend on each other.
A version for the Oracle database shipped in March, and a version for Microsoft SQL Server and Sybase Adaptive Server Enterprise (which I tested) shipped this month. Prices start at $12,000.
When source code has been analyzed, database calls in the code are matched to the related Transact-SQL procedures, views and base tables in the database.
Its then easy to see exactly which code components (even across machine boundaries) will need to change if a database table definition changes.