[InclinedPlane]

Funny story: at a, let's say, Fortune 50 tech company there was an investigation into why performance for a certain database query had become atrocious. The problem was that the query was against a table that started out quite small and then grew very large. And the database had been configured to use "query plan stability" to improve predictability of performance. However, the query plan that the db originally came up with for that nearly empty table was a full table scan, which was actually the fastest method under those conditions. Yet it continued to use a full table scan even as the table grew to many tens of millions of rows. It was a simple matter to switch the query to actually make use of the indexes that already existed.