I second this. I worked at a research company that had terabyte-scale SQL databases of curated data, and the tests would take 5 - 8 hours to run because they we

I second this. I worked at a research company that had terabyte-scale SQL databases of curated data, and the tests would take 5 - 8 hours to run because they were verifying query results rather than the queries themselves. This also meant tests would fail because of changes in the data rather than just changes in the code. I rewrote the entire test suite to match SQL statements against a symbolic SQL description, which turned out to be a much more robust and extensible solution.