wrote: Right. I also looked at it briefly, but I wasn't sure if we really want it. AFAICT, no-one has actually asked for that operator, it was written only to be an example of an operator that would benefit from the
knn-gist
with recheck patch.
Lack of recheck is major limitation of KNN-GiST now. People are not
asking
for that because they don't know what is needed to implement exact KNN
for
PostGIS. Now they have to invent kluges like this: [ query using ORDER BY ST_Distance ]
It's not apparent to me that the proposed operator is a replacement for ST_Distance. The underlying data in an example like this won't be either points or polygons, it'll be PostGIS datatypes.
In short, I believe that PostGIS could use what you're talking about, but I agree with Heikki's objection that nobody has asked for this particular operator.
"polygon <-> point" is for sure not ST_Distance replacement. I was giving this argument about KNN-GiST with recheck itself. "polygon <-> point" is needed just as in-core example of KNN-GiST with recheck.
Right. I don't think point <-> polygon is too useful by itself, but we need an example in core that could make use KNN-GiST recheck patch. We can't write a regression test for it otherwise, for starters.
Actually, we probably could've used the circle <-> polygon for that just as well...
Did you mean searching for circles or polygons in the last sentence?