This is suprising indeed.
Im my test using the v.out.postgis was still way faster than constructing
with postgis topology (about x3 I think).
Are you using v.out.postgis -l, with grass 7?
Grass is a topology that is more node centered, opposite to postgis
topology which is more edge centered.
It
It may not be required, if ST_Intersects() does what you need, but you can also
use ST_Relate() - whish will return polygons matching any spatial relationship
except disjoint - functionally equivalaent to "not ST_Disjoint()"
Cheers,
Brent Wood
From: Hugues François
To: Joseph Spenner ;
On Wed, Nov 12, 2014 at 10:51:34AM +0100, Rémi Cura wrote:
> Note you could have directly exported into postgis topology, which is slow
> but very convenient (stil faster than postgis topology conversion).
> I'm not a grass user,
> from what I understood you have to use the "-l" switch in the comma
Hugues: Yes, you are quite right. The ST_Intersects does exactly what I need.
Good stuff here.
Thanks again everyone for your patience! I probably should have tried a few
more of these before posting.
Cheers!Joseph Spenner
If life gives you lemons, keep them-- because hey.. free lemons.
Sorry for all the posts, but I think I found my answer. I can accomplish my
goal with 2 querries:
1) using the ST_Overlaps+2) using the ST_Contains
So, I just need to combine those 2 in 1 single query somehow. I'm thinking..
select ugcstring from polys where ST_Overlaps(ST_GeomFromText('POLY
Hi,
I think ST_Intersects will meet your needs :
SELECT zone,gid,state,name,ST_Asgeojson( geom )
FROM polys
WHERE ST_Intersects(ST_GeomFromText('POLYGON((-109 42,-108 42, -108 43; -109
43, -109 42))', 4269), geom)
Hugues.
Hugues François
Tourisme et systèmes d’information
Something I did notice though-- it seems that if the input polygon completely
surrounds a polygon stored in my database, it is not included in the result. I
read something about this here: http://postgis.net/docs/ST_Overlaps.html
"Returns TRUE if the Geometries "spatially overlap". By that we
Rémi: Yes, that worked perfectly. Thanks! My input poly will be stored in
another database (maybe just another table). It would be nice to perform the
query all on 1 line (get the poly and use it for the query), but I can query
the first table first to get the input poly, then use that for
Something like this?
SELECT zone,gid,state,name,ST_Asgeojson( geom )
FROM polys
WHERE ST_Overlaps(ST_GeomFromText('POLYGON((-109 42,-108 42, -108 43; -109
43, -109 42))', 4269), geom)=TRUE;
Cheers,
Rémi-C
2014-11-18 9:00 GMT+01:00 Hugues François :
> Hello,
>
>
>
> Maybe I don’t understand
Hello,
Maybe I don’t understand your problem very well but I think your query for
points should work with a polygon using ST_GeomFromText
(http://www.postgis.org/docs/ST_GeomFromText.html) for your input polygon or a
subquery if it stored into your DB.
Hugues.
De : postgis-users-boun
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