[postgis-tickets] [PostGIS] #4463: PostGIS raster ST_Intersects regression with pg12
PostGIS
trac at osgeo.org
Fri Jul 26 16:20:26 PDT 2019
#4463: PostGIS raster ST_Intersects regression with pg12
----------------------+---------------------------
Reporter: robe | Owner: Bborie Park
Type: defect | Status: new
Priority: blocker | Milestone: PostGIS 3.0.0
Component: raster | Version: trunk
Resolution: | Keywords:
----------------------+---------------------------
Description changed by robe:
Old description:
> Our PostGIS raster still relies on inlining, so the costing we added to
> functions in PostgreSQL 12 is making raster performance poor as many uses
> of ST_Intersects (raster variant are no longer inlining)
>
> Need to change raster ST_Intersects functions to be support function
> aware
>
> Example from Paul's data:
>
> DEMS https://pub.data.gov.bc.ca/datasets/175624/92g/092g06_e.dem.zip
> https://pub.data.gov.bc.ca/datasets/175624/92g/092g06_w.dem.zip
> buildings https://data.vancouver.ca/datacatalogue/buildingFootprints.htm>
>
>
> {{{
> raster2pgsql -I -F -s 4269 -t 56x56 092g06_e.dem dem092g06e | psql
> yvr_raster
> shp2pgsql -s 26910 -D building_footprints_2009 buildings
> }}}
>
> {{{
> ALTER TABLE buildings
> ALTER COLUMN geom
> TYPE geometry(MultiPolygon, 4269)
> USING ST_Transform(ST_Force2D(geom), 4269);
>
> CREATE INDEX ix_buildings_geom_centroid ON buildings USING
> gist(ST_Centroid(geom));
> }}}
>
> --this doesn't use an index on PostgreSQL 12 (though it has option of a
> centroid functional index and a raster ST_ConvexHull(rast) index
> -- TODO: test on 11, we suspect it will be able to use the indexes
>
> {{{
> SELECT b.*
> FROM buildings b
> JOIN dem092g06e d
> ON ST_Intersects(ST_Centroid(b.geom), rast)
> WHERE ST_Value(d.rast, ST_Centroid(b.geom)) <= 30
> }}}
>
> The issue as RhodiumToad explained on IRC is the
> ST_Intersects(raster,geometry), geometry,raster is still relying on
> _ST_Intersects which doesn't use the fancy function costing so is
> suffering from the high costs we've put in place.
New description:
Our PostGIS raster still relies on inlining, so the costing we added to
functions in PostgreSQL 12 is making raster performance poor as many uses
of ST_Intersects (raster variant are no longer inlining)
Need to change raster ST_Intersects functions to be support function aware
Example from Paul's data:
DEMS https://pub.data.gov.bc.ca/datasets/175624/92g/092g06_e.dem.zip
https://pub.data.gov.bc.ca/datasets/175624/92g/092g06_w.dem.zip
buildings https://data.vancouver.ca/datacatalogue/buildingFootprints.htm>
{{{
raster2pgsql -I -F -s 4269 -t 56x56 092g06_e.dem dem092g06e | psql
yvr_raster
shp2pgsql -s 26910 -D building_footprints_2009 buildings
}}}
{{{
ALTER TABLE buildings
ALTER COLUMN geom
TYPE geometry(MultiPolygon, 4269)
USING ST_Transform(ST_Force2D(geom), 4269);
CREATE INDEX ix_buildings_geom_centroid ON buildings USING
gist(ST_Centroid(geom));
}}}
--this doesn't use an index on PostgreSQL 12 (though it has option of a
centroid functional index and a raster ST_ConvexHull(rast) index
-- TODO: test on 11, we suspect it will be able to use the indexes
{{{
SELECT b.*
FROM buildings b
JOIN dem092g06e d
ON ST_Intersects(ST_Centroid(b.geom), rast)
WHERE ST_Value(d.rast, ST_Centroid(b.geom)) <= 30
}}}
The issue as RhodiumToad explained on IRC
http://irclogs.geoapt.com/postgis/%23postgis.2019-07-26.log is the
ST_Intersects(raster,geometry), geometry,raster is still relying on
_ST_Intersects which doesn't use the fancy function costing so is
suffering from the high costs we've put in place.
--
--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/4463#comment:1>
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