There where some interesting questions, but probably the most relevant came from Dave Glover from Microsoft when we were discussing the sales related implications of not having all pages on a website indexed & therefore not available for search.

Dave asked how could you ensure that all pages of database site were indexed by Google.
Although I did utter ‘sitemap’ at the event, I dont think answered this question as completely as it deserves.
Google’s Webmasters pages allow you to register a website and specifiy a related Google ‘sitemap’ file. This XML file explicitly lists all of the content your wish google to index – like the reverse role of a ‘robots.txt’ which tells the search engine spider which files (or directories) NOT to index.

The filename and location of the sitemap is completely at your discretion – a key point in this discussion.
My suggested approach is that a db query generating a list of all relevant records that will be presented as pages, along with the related dynamic URL.The output should render this page as XML compliant to the sitemap standard 

The sitemap generating page’s filename should be carefully stored in unindexed area (robots.txt !) so that it can’t be found to used harvest your db