One of the new products that Red Gate Software is working on is SQL Lighthouse, which is designed to track and alert you on "database drift", which are the changes in your schema. I hadn't really heard the concept in the past, though I've found there are a few people using the term to describe the changes being made to production that aren't inline with the development project that created (and updates) the database.

Vendors that sell products backed by a SQL Server database, like Microsoft Dynamics, often consider database drift to be a violation of their EULA. When a customer changes the database, even by just adding indexes, it causes them support costs, though arguably those costs are lower than if no indexes were ever added by enterprising DBAs.

However this also happens in databases built by companies. It seems there's no shortage of "quick fixes" in production, in addition to the "improvements" that DBAs and others seem to make to their live databases in order to solve some short term issue. I know there's a need for this, and even seen recommendations to ensure production differs from development schemas. However I haven't had many issues with this in the past and I've tried to prevent any drift.

Maybe because I'm a controlling DBA, or maybe because I've been lucky. In either case, while I've had to implement hot fixes and changes in production, it's been rare. Most of the time I've been able to backfill these changes in development (and test) environments, or delay the fix until it could be tested.

However I'm sure there's a need for a way to manage drift, and detect it as the number of databases you manage grows, so I'm excited by SQL Lighthouse and hope it helps DBAs avoid those late night phone calls by being aware of what's changing in their systems.