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What makes you say your geometries not is populated as expected? What do you get from: SELECT ST_AsText(geom) FROM table_part1; If you are using 1.5 and the problem is that the geometry column not is …

Hallo What I use to do in those cases is creating a table with the classes and joining against them or use a subquery to create a list of classes. I think that gives a more intuitive approach and I …

If it would have been a few million points to check distance between you could consider using knn-distance with PostgreSQL 9.1 and PostGIS 2.0. But I think you should do fine with something like? …

I guess you haven't installed PostGIS in the database. Run Create extension PostGIS; before creating the function

You are looking for ST_Azimuth http://postgis.net/docs/manual-2.4/ST_Azimuth.html

Yes, the geometry type is a varying length data type even if it is just a point. If you will get a performance issue depends on how fast you need things to happen and what you want to do. A few tho …

You mention PostGIS. If you want to use PostGIS, with the spatial functions and spatial index that comes with PostGIS you will have to use the PostGIS geometry or geographic data type. If you stor l …

Without reading all the details I think: You should use ST_DWithin instead You should cast to geography type, or just use the geography type instead of geoemtry type which makes ST_DWithin work with …

Edit: field names corresponding to the questions field name SELECT polygons.id , polygons.name , coalesce(sum(points.value),0) AS sum FROM polygons LEFT JOIN points ON ST_Intersects(polygo …

WITH points as ( SELECT DISTINCT on (p,id) (ST_DumpPoints(geom)).geom p from the_table ) SELECT count(*) number_of, p FROM points GROUP BY p ORDER BY number_of DESC limit 100; Some notes: The disti …

Edited Take a look at the doc: http://postgis.net/docs/manual-2.1/ST_Contains.html Sorry, I misread your question first. Interesting that it didn't work with your first syntax but with _st_contain …

I think your solution is quite elegant. I guess what you want to do that you don't succeed in doing is getting help from indexes distance ordering. From the query it looks like you are aware that t …

What do you mean by line = length? I guess what you mean is that your subquery will find the id of the shortest line. Then you ask in the outer query for a line with that id and some number less than …

SELECT wbn_uidn, sum(ST_Length(ST_Intersection(wgo_geom,wbn_geom))) FROM wbn, wgo WHERE ST_Intersects(wgo_geom,wbn_geom) GROUP BY wbn_uidn;

Leave the looping for the database. This is SQL. SELECT polygons.id, lines.id FROM polygons, lines WHERE ST_Intersects(lines.geom,polygons.geom); Put spatial indexes on the geometry columns.