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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3
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1answer
223 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
votes
1answer
28 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 ...
0
votes
2answers
98 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 ...
0
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0answers
75 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 ...
2
votes
1answer
111 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 ...
0
votes
1answer
51 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 ...
1
vote
2answers
122 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 ...
2
votes
1answer
237 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 ...
0
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0answers
103 views

within using Hibernate Spatial

I'm doing this query using postgis and working properly SELECT "public".zona."id", "public".zona.zts FROM "public".zona WHERE ST_Within ( Geometry ( st_GeographyFromText ...
0
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3answers
238 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 ...
0
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0answers
38 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
vote
1answer
46 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?
0
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0answers
67 views

pgrouting pgr_drivingdistance() query gives inconsistent results

So I have been working on a query(with the help of other stackexchangers :)) to get the edges in an isochrone from a particular point and then update the count_events field of those edges by some ...
0
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0answers
64 views

Displaying 3D city model from PostGIS 3D backend

I know that openlayers doesnt support 3D yet. I heard about Kartograph has 3D features but Does Kartograph support reading data from backend database especially PostGIS? I would like to create a 3D ...
0
votes
1answer
102 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. ...
0
votes
2answers
77 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 ...
0
votes
1answer
45 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 ...
2
votes
0answers
122 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 ...
1
vote
0answers
42 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 ...
1
vote
3answers
48 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, ...
0
votes
1answer
62 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 ...
-1
votes
1answer
191 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: ...
2
votes
1answer
95 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 ...
1
vote
2answers
65 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 ...
1
vote
0answers
52 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 ...
1
vote
1answer
97 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
votes
2answers
62 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 ...
1
vote
1answer
93 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) / ...
1
vote
1answer
47 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 ...
1
vote
1answer
48 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
votes
1answer
463 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 ...
0
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0answers
55 views

PostGIS: calculate width/length of rectangular surface

I have rectangular shaped surfaces (multipolylines) and I need to calculate the width and/or length.. they have a rectangular shape but they're not real rectangles. Is there a way to do this ?
1
vote
2answers
351 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
votes
1answer
241 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 ...
1
vote
1answer
44 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 ...
0
votes
1answer
74 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, ...
0
votes
0answers
270 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
121 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 ...
4
votes
3answers
424 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: ...
0
votes
0answers
93 views

Postgis performance: st_dwithin vs static buffer and st_contains

I have a table with a polyline column. I need to find which of those polylines are within 20 meters from a bunch of moving points. I can do this no problem with st_dwithin(). What I would like to know ...
1
vote
3answers
131 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: ...
0
votes
0answers
25 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 ...
0
votes
0answers
46 views

Transforming multiple LineStrings to shape for ST_Contains

I want to find cities, villages etc inside each region of Poland. For most of them querying something like this is enough: ... AND ST_Contains((SELECT way FROM planet_osm_polygon WHERE osm_id = ...
1
vote
1answer
72 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 ...
1
vote
1answer
70 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
votes
3answers
141 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
votes
1answer
396 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 ...
1
vote
1answer
126 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
292 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
votes
2answers
282 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 ...