On Mon, Jun 18, 2018 at 6:11 PM, Andres Freund <and...@anarazel.de> wrote: > On 2018-06-18 18:05:11 -0400, Tom Lane wrote: >> Andres Freund <and...@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. > > They're doing the opposite, right? I.e. they return "hypothetical > indexes", which then can be used by the planner. None of the ones I've > seen currently mask out an existing index. > > >> It's possible that they've all bit-rotted for lack of support, which >> would not speak highly of the demand for the feature. > > IDK, the DBA / developer crowd hitting issues like this isn't the same > as the crowd willing to update an external plugin that doesn't even do > quite what you want, and was more experimental than anything. >
Indeed. ISTR a conversation I had with someone on slack earlier this year about the validity of just manually updating indisvalid as a means for determining if an index could be safely removed (for the record, I did not recommend it ;-) DBA's are often willing to weedwhacker at things in SQL when the alternative is to learn C. Robert Treat http://xzilla.net
