Cases where full scans are better than indexes
“We’ll add an index when it gets slow” is saying “screw the guy who’s on call the night this system starts timing out”.<p>Invisible cliffs in your code that it will fall off at some unknown point in the future are the antithesis of engineering.<p>If you deliberately aren’t implementing indexing, know at what point indexing would begin to matter. Put in place guard rails so the system doesn’t just blow up unexpectedly.<p>There are 100% cases where <i>you shouldn’t use indexes</i>. That’s not the same thing as <i>being able to get away without an index</i>.