There was a fear that having to create an index on a table that large would take a long time, and I think some of it was also ego "I intentionally didn't add it in, because so and so reason". This was why I dug in and did my thing, debunk all the fear / opinions / rationalization. Sometimes you just gotta be able to tell people they're wrong supported with empirical evidence. That's how the team will grow. There is just no need to dance around facts. I remember having to tell the team, "taking a long time to run an index is no reason to avoid creating the index".