On Mon, Jun 18, 2018 at 2:57 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Admittedly, this isn't great in a production environment, but neither > would be disabling the index in the way you suggest. > > I think the actually desirable way to handle this sort of thing is through > an "index advisor" sort of plugin, which can hide a given index from the > planner without any globally visible side-effects.
The globally visible side-effects are the point, though. Some users desire cheap insurance against dropping what turns out to be the wrong index. FWIW, this isn't just a MySQL feature. Oracle has a similar feature. -- Peter Geoghegan