On Tue, Jun 19, 2018 at 12:05 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Well, what I was thinking about was that this functionality already
> exists (I think) in one or more "index advisor" plugins. It's possible
> that they've all bit-rotted for lack of support, which would not speak
> highly of the demand for the feature. But if we feel this is worth
> pulling into core, I think something along the lines of a GUC listing
> indexes to ignore for planning purposes might be a better design.
> It'd certainly dodge the issues you mentioned about lack of mutability
> of pg_index entries.
I know only one extension which does exactly that:
https://github.com/postgrespro/plantuner
It seems that it's still maintained.