On Mon, Jun 18, 2018 at 3:12 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Perhaps there are use-cases where you want globally visible effects,
> but the primary use-case Andrew cited (i.e. EXPLAIN experimentation)
> would not want that.
>
> Anyway, if we do it with a GUC, the user can control the scope of
> the effects.
I had imagined that those use cases would be the most common. Dropping
an index in production because it very much looks like it is unused is
always a bit nerve-wracking in my experience. It's often hard to be
100% sure due to factors like replicas, the possible loss of statistic
collector stats masking a problem, the possibility that there are very
important queries that do use the index but are only run very
infrequently, and so on.
--
Peter Geoghegan