Version 2.0 of PostGIS brought a heavy set of new extensions for the PostgreSQL object-relational database, adding greater support for spatial objects.

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341 views

raster2pgsql does nothing

I try to load rasters through raster2pgsql. I try to call it through pgAdmin command line, but when I call any raster2pgsql command (even raster2pgsql -G), it does nothing, I just get another line to ...
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2answers
206 views

problem merging polygons based on a column value - using Spatialite

edit: as I am unfamiliar with any tools I decided to try my luck with PostGis. I imported my data. and executed the query : create merged as select delomrade_code, st_union(geometry) from grunnkrets ...
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1answer
127 views

postGIS: what is more efficient: single or two-point search

I have seen different approaches to conducting searches. Which is the best approach in storing the data for database efficiency: saving both longitude and latitude points longitude latitude vs ...
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1answer
77 views

Local Coordinate System

I am currently evaluating the use of PostGIS (version 2.0) for: a project that will store 3D coordinates (x, y, z) data the data will have it's own local coordinate system which does not correspond ...
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1answer
229 views

Routes Consult with pgrouting / openlayers [closed]

I'm starting with pgrouting. After suffering a bit unable to put the data in osm postgis using osm2po with the excellent tutorial http://anitagraser.com/2011/12/15/an-osm2po-quickstart/ ran the sql ...
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1answer
51 views

Not empty geometry having blank text

i'm having problem with geometry column, for some rows i have geometry with blank text, this query will describe more the problem : select geom, ST_AsGeoJSON(geom), ST_Isvalid(geom), ST_IsEmpty(geom) ...
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1answer
568 views

How to create a buffer on a linestring with varying or increasing/decreasing width

I want to buffer rivers/streams for a topographic map. I'm using a PostgreSQL/PostGIS database. Usually, I create buffer with ST_Buffer with a constant width. For example, the width of a river buffer ...
0
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1answer
36 views

Expression with postgis

I'm using mapserver and PostGis and I want to draw a geometric table in mapserver. The trouble is when I connect mapserver to PostGis and I want to draw the objects but in different colours. I mean I ...
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2answers
337 views

UpdateGeometrySRID and ST_Transform are the same thing?

UpdateGeometrySRID actually transforms the coordinate system of my data? For in the PostGIS documentation it appears the trim ST_Transform (Returns a new geometry with its coordinates transformed to ...
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0answers
207 views

Function ST_Transform postgis 2.0

I've read many forum posts on the function ST_Transform but unfortunately was unable to resolve my doubts so I posted a new question. I have a spatial table SRID = 101010 and want to transform it to ...
3
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1answer
499 views

Is there any random data generator supporting geometry in PostGIS?

I found few random data generators for PostgreSQL (such as this one), but none supporting PostGIS geometry type, other than point. Making points would be quite easy, but for lines with multiple nodes ...
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1answer
118 views

Empty geometry resulting from pgrouting function

Let me start by saying I'm assuming I'm missing something very silly but I can't see it. I have a table of points and I'm trying to generate a polygon around each point that estimates a maximum of ...
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2answers
444 views

Find out whether geography point lies within geography bounds

I have three points: Point A Point SW Point NE I want to know if Point A resides within the bounds determined by points SW (for south-west coordinates) and NE (for north-east coordinates). I've ...
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1answer
510 views

Cannot find my schemas in QGIS's “Add PostGIS layers”

When I connect to my PostGIS database using QGIS's Add PostGIS Layers, I see only public topology pg_catalog information_schema My other schemas that I have created are not shown here. Anyone else ...
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3answers
875 views

ST_transform postgis

SQL within that zone is a point SELECT "public".zona.zts FROM "public".zona WHERE ST_Within ( ST_Transform ( ST_GeomFromText ( 'POINT(-30.033514 ...
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0answers
90 views

rasterize a geography polygon using postgis 2.1

I am still bit new to Postgis 2.1. I am trying to rasterize a polygon, meaning that I have a polygon of Syria and I want to create an empty raster that contains the shape and geography reference of ...
1
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1answer
173 views

Break line into 100m segments

I have a line geometry in PostGIS and I am wondering how I would break the line into 100m segments. Is there a function for this?
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1answer
230 views

How can I find the segment of a line that lies within a polygon using Postgis?

Given a "road", represented by a line, that crosses a "state", represented by a polygon: What is the SQL query I can use to find the segment of the road that is within the state? A concrete example. ...
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2answers
193 views

How to select the cross streets in postgis spatial table?

I've used ST_Intersects and ST_Crosses but between two different tables. I have a table of streets and intersections want to know them. For example select all streets that cross the Street A. Can ...
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1answer
66 views

query to get predicted location after traveling on pgrouting route for some hours, postgis 2, postgresql 9.3

I am using Postgis 2.0 on Postgresql 9.3 on Ubuntu 14.04 x64. I am trying to find an efficient way to fulfill this routing request. So I am able to get the shortest route using the source and target ...
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0answers
651 views

how do I create a RESTful PostGIS web Service Framework?

I have PostGIS tables that store vectors that want to show on Google Maps. Read the post http://gis.stackexchange.com/questions/22354/how-to-display-a-postgis-table-on-google-maps But one thing that ...
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0answers
65 views

Import raster to postgis and add a foreign key constraint

I use raster2pgsql to import raster files into a table with this command line: C:\Program Files\PostgreSQL\9.3\bin>raster2pgsql -s 4326 -M -F -a c:\temp\mun.tif public.basqui_raster | psql -U ...
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3answers
73 views

PostGIS2 have automatic BBOX indexing?

I need to compare millions of geometries by the && operator (BBOX). When CREATE TABLE see geometry type on PostGIS2, it do also something like INDEX ON t USING GIST(g)? or I need to express, ...
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1answer
217 views

Get latitude and longitude of each point forming a MultiLineString

A MultiLineString is formed by a sequence of points and each point has latitude and longitude. Use the sql below to get the latitudes and longitudes of each point so that my MultiLineString: SELECT ...
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1answer
341 views

how to build and install pgrouting-2.0 on postgresql-9.3 on ubutntu 12.04 Lts precise?

I try to build following instructions from this link https://github.com/pgRouting/pgrouting after downloading from the github. I have done the cmake command and there is my error output: ...
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1answer
99 views

PostgreSQL : how do I make this sum [closed]

I have this huge table with all the addresses of my country in it. Every house is an object, and there is a column for the streetname (or street ID) and a column for the housenumber. I want to make a ...
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2answers
75 views

How can I speed up these queries

I am trying to make some calculations using PostGIS and PostgreSQL. There are 3 important tables : wbn, wgo and wvb. These tables have about 500.000 objects in them (geometries). The problem is that ...
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0answers
124 views

PostGIS 3D Extrude function

I selected buildings from OSM (which represents my city). I insterted a new column 'height' and I filled with a random number exactly number 2, so every building have 2metres altitude. Buildings are ...
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1answer
164 views

3D functions with SFCGAL in PostGIS

I have this setup: "POSTGIS="2.1.2 r12389" GEOS="3.3.8-CAPI-1.7.8" PROJ="Rel. 4.8.0, 6 March 2012" GDAL="GDAL 1.9.2, released 2012/10/08" LIBXML="2.7.8" LIBJSON="UNKNOWN" TOPOLOGY RASTER" on ...
2
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2answers
77 views

Do I still have to use a template DB for PostGIS?

createdb mydb -T template_postgis Is this -T template_postgis still necessary in new versions of PostGIS? I never saw this db being different, it always has those 3 sql files you run there. Is this ...
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1answer
299 views

ST_Union to merge tables containing lines?

I have to build a street network with Postgis that will be used with pgrouting. I have two tables: 1) the_network (182 lines): is a MULTILINESTRING table. Having columns road_name (varchar) / ...
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1answer
60 views

Trying to understand / troubleshoot intersection behavior of postgis

I'm trying to calculate the percent of intersection between two polygons using postgis. I was able to do so successfully for 90% of my polygons, but about 1500 have very unexpected values. I ...
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1answer
68 views

Weird ST_Contains behaviour

I'm creating a polygon and then checks whether one of the origin points is contained inside the polygon. To my surprise, I get False (?!) What is wrong here? SELECT ST_contains(ST_GeomFromText('POINT ...
3
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1answer
2k views

Improve speed of PostGIS “nearest neighbor” query?

One of the features of the Python/Django/PostgreSQL web application I'm building is that a user will be able to see the 100 other users who are nearest to them, sorted by distance. I'm using PostGIS ...
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2answers
691 views

Start postgresql+postgis without installation on Windows

I have used Windows7x64 and want start PostgreSQL+POSTGIS without installation process. I copy PostgresSQl\9.1 folder from other laptop to c:\opt. I need create .bat file with enviroment variables and ...
2
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1answer
568 views

POSTGIS: function st_collect(geography) does not exist

I am trying to use some Geography functions, but I am getting an error that (all) functions are not existing. I have checked other Stackexchange posts (e.g. this one), but the solutions did not work ...
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1answer
47 views

PostgreSQL : question about SELECT .. WHERE .. = max()

If you have, for example; SELECT * FROM data WHERE line = min( (SELECT length FROM lines) ) AND number < 500; (It's just an example, not a real code) How does PostgreSQL react when the ...
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1answer
90 views

Postgis query not using the spatial index

I've been using postgres8.3/postgis1.5 for some time, and it works well. I've moved my entire database to a new, faster machine and upgraded to postgres9.3/postgis2.1 using pg_dump/postgis_restore.pl, ...
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0answers
670 views

Problems moving POSTGIS database from postgresql 8.3 to 9.3 using Navicat

I am using Navicat 11 to move a POSTGIS database from 8.3 to 9.3 on Mac OS X 10.9. I have installed PostgreSQL 9.3 and PostGIS with homebrew (brew install postgresql postgis) and everything looks ok. ...
2
votes
1answer
237 views

Problem with matching a buffer in Openlayers and the same buffer in PostGIS query

I am using a buffer tool to create a buffer on my base map in Openlayers. In addition to creating and visualizing this buffer, I pass the center point and radius to a query. The query collects all ...
5
votes
3answers
1k views

How to create random points in a polygon in PostGIS

I have a polygon layer, and would like to generate random points in each polygon. An initial searching in Google resulted this website which presents a function for this purpose: ...
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3answers
232 views

Geometry vs geography for line-to-polygon intersection

I have two WGS84 NAD83 shapefiles, one polygonal, the other containing lines: Geometry: Polygon Feature Count: 1294 Extent: (-79.761059, 44.991143) - (-57.105486, 62.582865) Layer SRS WKT: ...
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0answers
26 views

Postgis and osm2pgsql: find all cities that belong to selected state [duplicate]

I'm pretty new to postgis, so I don't quite understand it's mechanisms yet. My task is to build database with relations: +---------+ +------------+ +----------+ | country | | adm_unit ...
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1answer
137 views

ST_AsLatLonText returns wrong data

I want to list all cities in lubelskie vovoidenship, which is relation 130919. I also want to get latLong data for each city. To perform this I do: SELECT name, ST_AsLatLonText(way), place ...
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1answer
130 views

Problem with runing a loop in a query in PostGIS

I am new to PostGIS and I have a question which can't solve. I have a table of buildings each having a value for number of people living in it. I would like to calculate the total value (sum of number ...
2
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3answers
208 views

Problem with result of query in PostGIS

I run the following query and irrelevant of the point coordinates and radius I always recieve all the records of the table I'm querying. Can anyone point out what the problem could be with this query? ...
2
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1answer
966 views

PostGIS: How to ST_Clip() a raster with a polygon?

I have done: Import a SHP file into PostGIS by PostGIS SHP loader GUI. Import a raster into PostGIS: \raster2pgsql -I -s 4326 landsat.TIF -t 500x500 public.landsat > query.sql After importing ...
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1answer
223 views

Problem with using a circle as polygon for querying PostGIS

I'm trying to query PostGIS and find some object features that intersect with a circular buffer created by the user using OpenLayers, JavaScript and PHP. I use the following code for creating the ...
2
votes
1answer
504 views

Problem with reading data from PostGIS as KML file using PHP

I am using the following PHP code in order to read data from PostGIS and save it in KML format as a file. When I load the page a document with ".PHP" extension is returned (not .kml) which inside has ...
2
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2answers
669 views

Problem in running query on PostGIS using PHP

Would you kindly help me solving this problem. I'm trying to use the PHP code provided here in order to read geo-data from PostGIS. The code seems clear without any problem (also nobody has ...