#997: ST_Union performance degradation from GEOS 3.6.x -> 3.7.x
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Reporter: greenlaw | Owner: geos-devel@…
Type: defect | Status: new
Priority: major | Milestone:
Component: Default | Version: 3.7.0
Severity: Significant | Resolution:
Keywords: union |
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Comment (by greenlaw):
@mdavis Yes, the `ST_SnapToGrid` workaround seems like it should work
perfectly for me as long as I use a small enough value (0.1 produced
`ERROR: GEOSUnaryUnion: TopologyException: Input geom 1 is invalid: Self-
intersection at or near point -15008907.701449277 7619503.4876811597 at
-15008907.701449277 7619503.4876811597`).
Not terribly concerned about precision here, but 0.001 seems to work just
fine, and the command completes in 79 sec. The resulting geometry looks
good to me.
I will put this change into production - don't expect any issues but will
be sure to report back if I run into anything.
Will be happy to test any potential fixes you guys come up with down the
road.
Thanks so much for your help.
{{{
EXPLAIN ANALYZE SELECT ST_Union(ST_SnapToGrid(ST_Buffer(wkb_geometry,
100.0), 0.001))::geometry(Geometry,
3857),category,vteccode,prod_type,validtime,starttime,endtime FROM
public.nws_haz_hang_201910 GROUP BY
category,vteccode,prod_type,validtime,starttime,endtime;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------
HashAggregate (cost=10.32..10.47 rows=10 width=706) (actual
time=33352.916..79931.923 rows=5 loops=1)
Group Key: category, vteccode, prod_type, validtime, starttime, endtime
-> Seq Scan on nws_haz_hang_201910 (cost=0.00..10.10 rows=10
width=706) (actual time=0.006..0.041 rows=21 loops=1)
Planning time: 0.133 ms
Execution time: 79931.984 ms
}}}
--
Ticket URL: <https://trac.osgeo.org/geos/ticket/997#comment:11>
GEOS <http://trac.osgeo.org/geos>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite
(JTS).
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