Hi folks
first of here some system informations:
Server: Ubuntu 12.04 LTS, 16GB RAM 1TB 4x SSD HW Raid
PostgreSQL 9.1.5 on x86_64-unknown-linux-gnu, compiled by gcc
(Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3, 64-bit
POSTGIS=2.0.0 r9605 GEOS=3.3.3-CAPI-1.7.4 PROJ=Rel. 4.7.1, 23
September 2009
.
De : postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] De la part de Thomas
Klemmer
Envoyé : mardi 11 septembre 2012 11:09
À : postgis-users@postgis.refractions.net
Objet : [postgis-users] ST_DWithin is not using SpatialIndex
Klemmer
*Envoyé :* mardi 11 septembre 2012 11:09
*À :* postgis-users@postgis.refractions.net
*Objet :* [postgis-users] ST_DWithin is not using SpatialIndex with
Subquery
Hi folks
first of here some system informations:
Server: Ubuntu 12.04 LTS, 16GB RAM 1TB 4x SSD HW Raid
PostgreSQL
Hi All,
Running 1.3.5 still :). Found some unexpected (to me), but
pleasant behavior with ST_DWithin. What we're doing is creating a function
that we can use to randomize a point within a minimum and maximum bounds.
Our original approach was to generate the geometry of the
From: postgis-users-boun...@postgis.refractions.net
[mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Stephen
V. Mather
Sent: Tuesday, October 25, 2011 11:04 AM
To: postgis-users@postgis.refractions.net
Subject: [postgis-users] ST_DWithin-- unexpected behavior?
Hi
Thanks. I started using GIST.
It works.
Thanks,
Sairam Krishnamurthy
+1 612 859 8161
On Thu, May 5, 2011 at 8:39 PM, Ben Madin li...@remoteinformation.com.auwrote:
Sairam,
On 06/05/2011, at 5:50 AM, Sairam Krishnamurthy wrote:
Table structure: lat AS double, lon AS double, spatialPoint
All,
Table structure: lat AS double, lon AS double, spatialPoint AS point.
I have a query that uses ST_DWITHIN. I was under the impression that this
function will use the gist index on spatialPoint.
Index query:
CREATE INDEX table_spatial_index ON table USING btree (spatialPoint);
Select
Sairam,
On 06/05/2011, at 5:50 AM, Sairam Krishnamurthy wrote:
Table structure: lat AS double, lon AS double, spatialPoint AS point.
I have a query that uses ST_DWITHIN. I was under the impression that this
function will use the gist index on spatialPoint.
Index query:
CREATE INDEX
Hi,
I have been trying, with no luck, to implement a query to return me all the
pairs of rows that are within a certain range of each other. I searched the
forum before trying to find a solution but I haven't been able to. Sorry if
there is a solution to this problem already that I didn't see.
Robert,
On 01/03/2011, at 4:47 PM, robertvc wrote:
I have been trying, with no luck, to implement a query to return me all the
pairs of rows that are within a certain range of each other. I searched the
forum before trying to find a solution but I haven't been able to. Sorry if
there is a
:
From: Paul Ramsey pram...@opengeo.org
Subject: Re: [postgis-users] ST_DWithin Performance
To: PostGIS Users Discussion postgis-users@postgis.refractions.net
Date: Sunday, February 13, 2011, 11:42 AM
How many records get returned when you drop the LIMIT? If you have to
sort 700K things
On Fri, Feb 11, 2011 at 02:27:16PM -0800, Carl S. Yestrau Jr. wrote:
Table schema:
Table public.geobits
Column |Type |
Modifiers
When I removed the ORDER BY created_on DESC the results were almost
instantaneous (which makes sense as it just returns the first 'x'
result defined by LIMIT). I don't have access to the machine at the
moment, but can get the plan for that if it's helpful.
I'm pretty confused why things are so
How many records get returned when you drop the LIMIT? If you have to
sort 700K things into order, I can see that taking a second or two.
P.
On Sat, Feb 12, 2011 at 2:16 PM, Carl S. Yestrau Jr.
c...@featureblend.com wrote:
When I removed the ORDER BY created_on DESC the results were almost
Hi Paul,
~700K records get returned if I drop the LIMIT. Thanks for the feedback.
On Sat, Feb 12, 2011 at 2:42 PM, Paul Ramsey pram...@opengeo.org wrote:
How many records get returned when you drop the LIMIT? If you have to
sort 700K things into order, I can see that taking a second or two.
On Thu, Feb 10, 2011 at 03:37:34PM -0800, Carl S. Yestrau Jr. wrote:
I have a geography(Point,4326) column with a gist index with ~700K
records. A simple query using the ST_DWithin() is taking about 15
secs. Any pointers from the resident experts?
show explain analyze yourselect output ?
Thanks Mark,
Here's the additional information, the ORDER BY created_on DESC seems
to be the issue even though it's indexed.
Table schema:
Table public.geobits
Column |Type |
Modifiers
I have a geography(Point,4326) column with a gist index with ~700K
records. A simple query using the ST_DWithin() is taking about 15
secs. Any pointers from the resident experts?
Arch Linux x86
postgis-1.5.2-1
postgresql-9.0.2-2
___
postgis-users
Hi all
At the first time i used ST_Contains but it take a long time, so I used
ST_Dwithin to improve the performance for the query statement but i don't
know it is correct or not.
I would like to know my points are within in polygon or not:
SELECT id, geom
FROM my_neighbour
WHERE ST_Dwithin
Hallo
What you are doing with ST_Dwithin is to check if your geom and geometry have
parts closer to (or exactly) 0.1 mapunits from eachother. If you are using
a meter based SRID then you are checking if they are within 0.1 meters from
eachother. So actually in this case your points can
Hi Nicklas
Actually the points can be outside the polygon and returning true but it can
be tolerance about 1 meters outside.
I'm using SRID: 4326. I would like to know 0.1 with the projection 4326
is equal 1 meter or not ?
I used ST_Intersects (geom, geometry); but it's really slow, I don't
Ok
The distance of 0.1 degree in east west direction will vary depending on
how far from the equator you are.
How many points is there in your dataset?
Do you see if the index is used?
/Nicklas
2010-05-25 nguyen liem wrote:
Hi Nicklas
Actually the points can be outside the polygon and
Hi Nicklas
my dataset about 100.000 rows and after run my query i get about 15.000
rows. I has created index for geom field but it was improve the
perofrmance for ST_intersect
I used SRID 4326, but I don't know how to convert from degree to meter.
Cheers
On Tue, May 25, 2010 at 3:43 PM,
Hi Nicklas
sr for the mistake ... field but it *was not* improve the perofrmance for
ST_intersect
Cheers
On Tue, May 25, 2010 at 3:53 PM, nguyen liem liemnguye...@gmail.com wrote:
Hi Nicklas
my dataset about 100.000 rows and after run my query i get about 15.000
rows. I has created index
The polygon you are testing against, is it very complex?
How long time does it take?
did you analyse the table after adding the index?
/Nicklas
2010-05-25 nguyen liem wrote:
Hi Nicklas
sr for the mistake ... field but it was not improve the perofrmance for
ST_intersect
Cheers
On
HI Nicklas
If i use ST_Intersect that take 30s (got 15356 rows)
If ST_DWithin: 5s (got 15482 rows)
I see ST_DWithin is really faster than ST_Intersect. It got more neighbours
but it's not a problem.
One more question, if i would like to use ST_DWithin in projection WGS84 and
the radius is in 1
On May 25, 2010, at 5:43 AM, nguyen liem wrote:
One more question, if i would like to use ST_DWithin in projection WGS84 and
the radius is in 1 meter, how to do that?
As someone else said it depends on the latitude you are dealing with, but you
take the circumference of the earth at your
Hi Charles
Thanks for your answer, i can understand a little, i will try to research
more.
One more time, i would like to say thank you with you and Nicklas.
Cheers
On Tue, May 25, 2010 at 6:47 PM, Charles Galpin cgal...@lhsw.com wrote:
On May 25, 2010, at 5:43 AM, nguyen liem wrote:
One
Hi,
I have a database stored in WGS84 EPSG:4326
I would like ti find objects within a distance from a lat/lon point.
1) If i use 1 degree as the distance, will I then get an eliptic search area?
2) Will i find objects on the other side of the Datum shift border if I enter a
point like lat=60°,
On 11 May 2010 07:34, Malm Paul paul.m...@saabgroup.com wrote:
Hi,
I have a database stored in WGS84 EPSG:4326
I would like ti find objects within a distance from a lat/lon point.
1) If i use 1 degree as the distance, will I then get an eliptic search
area?
2) Will i find objects on the
Would something like this be inefficient? I store data in a geometry
type, as I don't really care about the spheroid accuracy, as my
location queries are mostly less than 30 km apart. So...
SELECT ST_AsGeoJSON(location), title, description
FROM event
WHERE ST_DWithin(location::geography,
I am a newbie, could somebody explain what distance transformation should i
use to eliminate discrepancy in results for the following 2 queries
1) SELECT * from table1 where st_dwithin(geom1, geom2, distance);
*(Note, geom1 and geom2 are in SRID 4269)
*
2) SELECT * from table1 where
Hi All,
I have installed PostGIS 1.2.1 version but I could not able to find out
st_dwithin() in it. In which version this function will be available?
Thanks Regards,
Santosh Gaikwad
Senior Software Developer
Saama Technologies (India) Pvt Ltd.
6th Floor West Wing, Marisoft III,
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