PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.

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3
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1answer
347 views

How to connect particular sets of points with (poly)lines?

I think my problem is quite easy to be solved by the most postgis-users, but i am a bloody beginner: i have a timestamped point-table representing GPS-tracked places of different cars. To distinguish ...
5
votes
1answer
437 views

adding multiple points to a linestring in PostGIS

Though a newbie to PostGIS, I'm having trouble solving something that I think should be farily straightforward. I have two linestring tables, both consisting of simple, 2-node line objects: one has ...
7
votes
2answers
261 views

Update database row with points that fall within polygons

All, I have a PostGIS/Postgresql DB that has two tables in it. One with point geometries and the other that represents country boundaries as polygons. I would like to add the country name that each ...
1
vote
0answers
23 views

How do I draw a square on a vector layer from PostGIS? [duplicate]

Possible Duplicate: Is there a tool/plugin/script for QGIS that would allow for manual corrections to vectors and also allows for connection to postGIS? I am trying to draw two squares on a ...
3
votes
3answers
202 views

How can I draw squares in PostGIS layers at different angles?

I am trying to draw two squares on a 45-degree angle and then merge them using PostGIS to edit. QGIS can draw squares but only on a perpendicular plane (eg, 0, 90, 180), and I need to be able to draw ...
1
vote
1answer
770 views

CGI mapserver with PostGIS layer: pass SQL WHERE clause in URL paramaters

I use a third-party software to generate a mapfile and serve them on a OpenLayers based interface from a postgis database. The postgis table, representing the movements of monks in a specific area, ...
11
votes
3answers
603 views

How to add offsets to the route?

Edited: I want to ilustrate my question. Suppose that you're in "Point A" and want to go to "Point B". This points wouldn't be in "at_2po_4pgr" table cause aren't source/targets nodes. Then, I ...
9
votes
3answers
2k views

How to install PostGIS on Windows?

I want to create an application platform based on PostGIS data. I read the documentation where I saw the prerequisite to install GEOS, GDAL and Proj4. The main problem is I am using windows platform. ...
3
votes
1answer
199 views

Road layers appearing as points in GeoServer previews - both openlayers and GeoExp

I am wondering why my roads layer keeps appearing as points when previewed inside GeoServer - layer preview using both the OpenLayers and GeoExplorer options. The data are imported from PostGIS. I ...
2
votes
1answer
384 views

Remove stale/obsolete geometry columns from the geometry_columns table

I understand that the function Populate_Geometry_Columns() inserts records in the geometry_columns table for geometry columns that are not yet listed there. However, an invocation of ...
3
votes
1answer
255 views

Does QGIS DB Manager plugin lock PostGIS transactions?

I do most of my geospatial analyses in PostGIS 2.0 using PgAdmin III. I use QGIS 1.8 for visualizing my data but also for querying my database using the DB Manager plugin. Sometimes (quite often ...
5
votes
1answer
227 views

How to cache PostGIS views?

Does anyone knows if there exists a caching system for views or queries in postgis? I have a system that gives information through a webpage using a postgis view as backend. The problem is that, ...
4
votes
0answers
327 views

Geoserver WMS-T backend problems

I've been trying to set up a few timed WMS layers in GeoServer. They're simple enough, of the form ID(PRIMARY KEY) REGION DATE VALUE so for every region and date you have some value, e.g. the ...
2
votes
1answer
798 views

How to fix 'GEOSDifference: TopologyException'?

Why does Postgis throws an error in this SQL? Error: ERROR: GEOSDifference: TopologyException: found non-noded intersection between LINESTRING (-5.67027 43.5374, -5.67085 43.5376) and LINESTRING ...
4
votes
2answers
600 views

How to programmatically create exports from PostGIS database into different file formats (e.g. shapefile, dxf, dgn,…)?

Is there a kind of wrapper/library written in python which would enable me to programatically create exports from postgis database into different file formats (most common being, shapefile, dxf, ...
6
votes
2answers
777 views

PostGIS - area-weighted calculation on an intersection

I'm trying to learn postgis sql by performing some familiar operations from ArcGIS. Here, I want to perform an area-weighted calculation of certain populations on the intersection of a set of parcels ...
1
vote
1answer
171 views

How can i symbolize a map dynamically by data stored in mysql database in many tables (these tables have relationship through Primary Key and FK)

How can i symbolize a map dynamically by data stored in mysql database in many tables (these tables have relationship through Primary Key and FK). For instance "Disease Name"(chosen from drop down ...
3
votes
1answer
161 views

PostGIS & Geoserver: One large vector layer or many small layers?

I have a geoserver that displays some basic country data for Brazil at a course spatial scale (1:1 milion). Now the geography institute (IBGE) is making available the topo sheets at 1:250,000 scale, ...
2
votes
1answer
48 views

ST_HasBBOX does not exists

I have the lastest PostGIS version. When I query: select ST_HasBBOX(the_geom) from table_geom limit 1 I get this error: ERROR: function st_hasbbox(geometry) does not exist Why this function does ...
1
vote
0answers
49 views

Converting geometry_dump to Point geometry vertex

If this was a Point geometry 010100000001DE02098A1B52C090A0F831E62E4640, is it possible to represent the above geometry_dump Point Vertex. I am trying with St_collection...,
4
votes
1answer
1k views

How can I find start and end points from a road layer?

I have a shapefile with geometries MultiLineString and Point. I have loaded the shapefile into PostGIS. From that table I cannot find any (lon,lat) except geometrical values with some SRID,.... ...
3
votes
0answers
138 views

Create a consistent topology using pgrouting

I'm developing an application that needs routing information for certain cities. First, I downloaded a openstreetmap datafile (*.osm) and then I imported it into a postgreSQL database using ...
8
votes
2answers
781 views

How to add vertices to existing linestrings?

If I have Linestring(1 2, 1 5, 1 9) and a Point(1 3) Is there any function that can merge linestring and point preserving the order so output would be: Linestring(1 2, 1 3, 1 5, 1 9)
5
votes
1answer
329 views

Can you synchronize tables between ArcSDE(MSSQL) and PostgreSQL(PostGIS) regularly?

I have spatial tables in ArcSDE 10.1 (MSSQL 2008 R2) geodatabases and need to update the same spatial tables in PostgreSQL 9.1(PostGIS 2.0.1) geodatabases. Basically I use my ArcSDE environment for ...
3
votes
2answers
143 views

Why I see different data from PostGIS and ArcSDE

I have installed ArcSDE 10 on PostgreSQL 8.4.3 with PostGIS 1.4.2. I did some tests. I imported one feature layer with 8500 features into ArcSDE through ArcCatalog. and I deleted 8499 features in ...
4
votes
2answers
490 views

Creating many origin-destination routes with pgRouting

I'm using a PostGIS / pgRouting database setup with a road network. I'm trying to create an origin-destination table with the complete route information, so not just the sum of the length, like in ...
4
votes
1answer
229 views

Exporting 3D geometry from PostGIS 2.0

I have a table containing 3D geometry in a PostGIS 2.0 database (the geometry is of type LINESTRING Z). I need to get the geometry out and into a DXF, DGN or 3D Shapefile. What is the easiest way to ...
3
votes
2answers
516 views

Why does Ogr2Ogr Postgres import fail?

I have a lot of S57 files that need to be imported to PostgresDB. The process takes over 2 hours. In order to improve performance, I have tried using PG_USE_COPY to use copy instead of DB inserts. I ...
2
votes
1answer
409 views

Querying PostGIS Raster with MultiPoint

For one of my projects using PostGIS 2 I have a table with GPS tracks (igc_files). It holds records including a MULTIPOINT() column that has about 1,000 points for each record and a column that has an ...
2
votes
1answer
75 views

What is the difference when measuring in units rather than meters?

I have a function that takes a point and compares it with lines that are stored in PostGIS and then gets the line closest to the point. Initially I did not transform the data because I did not think ...
6
votes
1answer
95 views

PostGresql and PostGIS courses in Canada

I have been looking for good professional courses for learning more than just the basics for PostGresql nd PostGIS. I have found a number of good courses, but they seem to all be in the US. I was ...
2
votes
1answer
272 views

ST_Collect runs out of memory

I am trying to calculate the convexhull for an entire table containing 3 200 000 records. the_geom is of type POINT: SELECT ST_ConvexHull(ST_Collect(the_geom)) FROM mytable; After 1-2 seconds it ...
3
votes
3answers
222 views

Setup a map server that runs from USB to whatever computer it is connected?

I would like to have a USB that I can bring with me to any computer. That USB should hold a map server, so that the client computer wont need internet and avoid using OSM or Google maps or any other ...
1
vote
0answers
170 views

Imposm full database schema import template

I noticed that the default imposm template for importing OSM data into postgis lacks some types of features (powerlines for example). I was searching the web to find a complete schema import template ...
1
vote
1answer
168 views

Instructions for building a Flex App using open source PostGIS DB and Geoserver

Anyone have a link for a good guide on how to build a Flex app to work with Open source REST services? I am familiar with how to do it in ESRI and Arc Server Manager, but don't want to pay for a ...
2
votes
2answers
296 views

Wanting to build Web Mapping Application

I am wanting to build a web mapping application and am trying to gather all the pieces that I'll need. Is it possible to build REST services with opensource Geoserver from an ArcMap document and tools ...
2
votes
1answer
215 views

how to create an outline polygon (footprint) from raster data with postgis?

how can I create a polygon, containing the actual outlines (aka footprint) of a raster file with postgis? I just need the outlines of the data containing parts of the raster. ST_PixelAsPolygon ...
15
votes
4answers
5k views

How to reproject all geometries in a PostGIS table?

I created a spatial table with SRID:4326. Now I want to change total projection to SRID:32644 into a new table. The old table should remain unchanged.
2
votes
1answer
299 views

How to do Reverse Geocoding from MySQL/PostGIS Sql ???

I want to do reverse geocoding from MySQL or PostGIS SQL. I have shapefile up to town level of India. So I have a geometry boundary for each town. What I want is to first find the nearest point ...
4
votes
1answer
267 views

extracting pixel value from a table in postgresql

I have a table in postgresql that contains ID, row number, column number, pixel value and centroid of the pixel in WGS84 lat-lon system(4326). How could I extract the pixel value by giving a point in ...
6
votes
0answers
573 views

Getting ST_Difference between two different tables in postgis [closed]

One table has a series of grid squares in it, and the other has millions of voronoi polygons in it. I need to create a table that has the difference between the two of the them so that I effectively ...
10
votes
1answer
487 views

How to render a table with mixed geometry types in QGIS?

I created a table with geometry type "GEOMETRY" AND inserted data of point, line and polygon type. My question is how to show this spatial data Qgis not supporting for geometry type "GEOMETRY".
1
vote
1answer
405 views

PostGIS Create Table with Geometry

I have written a query that will create a table and perform a GROUP BY from an existing spatial table, but the table does have the geometry. I am wondering where, and what, in this query I put to ...
2
votes
2answers
1k views

How to import shp files into postgresql with PostGIS?

I'm a new user of postgreSQL/postgis but I'm having a problem. I'm trying to import some shapefiles (which open perfectly in QGIS or ArcGIS but create an error when i import them). The problem is not ...
1
vote
1answer
283 views

Why is my PostGIS transformation not working?

I am using a PostGIS query to find the intersection of two streets, and then transform the results into lat/lon. The street database's current SRID is 6856, a projection I added to PostGIS myself; and ...
2
votes
0answers
193 views

Error recognising password; importing OSM to PostGIS in QGIS

When selecting OSM Tools (Import into PostGIS) , attching my .osm file in the Input option, selecting my OSM Database, and then clicking run, I am prompted to enter a password for connection. "Enter ...
6
votes
2answers
412 views

Find points of interest near a path?

Imagine a table of points of interest along with lat/long. The user identifies two of these points. I want to do the following: Calculate a great-circle path between these points Find all POIs that ...
4
votes
1answer
145 views

Is there a Postgis SQL Coding Style Guidelines?

Most programming languages have Coding styles. Some have defined standards, other have just some code of conduct that the majority of programmers follow. Standard coding styles are have obvious ...
3
votes
1answer
97 views

Why can't I add numeric(n,m) field values to PostGIS geometries in QGIS 1.7.1? [closed]

Actually I'm using QGIS 1.7.1 to create and visualise some geodata hosted by PostgreSQL 8.4 and PostGIS 1.4.0. The geodatatable is defined like this: CREATE TABLE u2_baum ( baum_id integer NOT ...
2
votes
2answers
638 views

What's the fastest way to search for polygons that intersect with others?

I'm querying the database for searching polygons that intersect with others, but is very slow research, wanted to increase the speed. I thought of using sphinx, solr, elastic search googled but did ...