Hi Gregory Kaufman,
The database is automatically updated and the data you have will not be lost. We use Nolics layer to define tables in our database. When you replace all required folder and assemblies the database tables version is checked - if the value is different an upgrade/downgrade is processed.
The only possible loses that I have seen could be related if you have workflow and not published items - you have some staged content - let's say in status "For Approval". Then, the content item will not be deleted. The last published version will be used.
I hope this helps.
All the best,
the Telerik team
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