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Aug 7, 2018 at 18:07 history tweeted twitter.com/StackGIS/status/1026892544280551425
Jul 11, 2017 at 12:14 comment added coding_bird Let us continue this discussion in chat.
Jul 11, 2017 at 12:13 history edited coding_bird CC BY-SA 3.0
changed version of docs
Jul 11, 2017 at 12:01 comment added coding_bird OK. It seems that PostGIS 2.2.2 does not use "real KNN distance" - whereas 2.3.2 does support it.
Jul 11, 2017 at 11:55 comment added John Powell Perhaps excessive information, but: PostgreSQL 9.5.6 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 5.3.1-14ubuntu2) 5.3.1 20160413, 64-bit and POSTGIS="2.3.2 r15302" GEOS="3.5.0-CAPI-1.9.0 r4084" PROJ="Rel. 4.9.2, 08 September 2015" GDAL="GDAL 2.1.3, released 2017/20/01" LIBXML="2.9.3" LIBJSON="0.11.99" RASTER, ie, 9.5.6 and 2.3.2 :-) I have also tried on 9.4 and 9.6, with 2.2 and 2.3, and get the same, ie, correct result. Very bizarre.
Jul 11, 2017 at 11:53 history edited coding_bird
edited tags
Jul 11, 2017 at 11:48 comment added coding_bird When I put the ASC I get the same result as before. Which Postgres/PostGIS version are you using?
Jul 11, 2017 at 11:44 comment added John Powell I can't. When I run your code, I get green first and then blue, as you would expect. What happens if you put ASC at the end of the ORDER BY. I realize that it shouldn't be the case, but just to check.
Jul 11, 2017 at 11:33 comment added coding_bird @JohnPowellakaBarça I updated my question. Can you explain this behavior of PostGIS? Thanks :-)
Jul 11, 2017 at 11:32 history edited coding_bird CC BY-SA 3.0
provided minimal example
Jul 11, 2017 at 7:40 comment added John Powell Well, you say the answer is incorrect, but it is impossible for us to test without some geometries and the expected results. The query itself looks ok.
Jul 11, 2017 at 7:36 comment added coding_bird @JohnPowellakaBarça do you need more information? Which numbers shall I provide?
Jul 10, 2017 at 15:08 comment added tilt Can you add a field ST_Distance(ST_Point(1,2)::geography, ST_Centroid(my_polygons.geom)) AS cent_distance to be sure of this?
Jul 10, 2017 at 12:56 comment added John Powell The <-> operator is finding the closest polygon by the kNN distance and ordering results accordingly, but your actual distance metric is being determined by ST_Distance, which will definitely return the distance to the nearest point on exterior of the polygon, not the centroid. It is a bit hard to tell without some raw numbers, though.
Jul 10, 2017 at 11:50 history asked coding_bird CC BY-SA 3.0