Andres Freund <andres@anarazel.de> writes:
> On 2018-06-18 17:57:04 -0400, Tom Lane wrote:
>> 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.
> Although I'm a bit doubtful that just shoving this into an extension is
> really sufficient. This is an extremely common task.
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.
regards, tom lane