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

learn more… | top users | synonyms

-1
votes
1answer
20 views

Rotate Polygon to be Parallel with the X Axis

By default, PostGIS calculates the Envelope or Extent of a polygon based on the bounding box of the polygon ((MINX, MINY), (MINX, MAXY), (MAXX, MAXY), (MAXX, MINY), (MINX, MINY)). This gives a result ...
3
votes
1answer
38 views

Poor performance with storing large rasters in PostGIS and visualising in QGIS

my question concerns the use and performance of several software tools in conjunction, namely PostgreSQL, PostGIS, QGIS, and GDAL. I'm a long-time ArcGIS, Python, and R user who is interested in ...
0
votes
0answers
16 views

Any experience or tips for using qgis with postgis layers? [duplicate]

we want to replace our shapefiles with postgis layers for editing in QGIS. We plan to edit 1 Layer with 5 people at the same time is this possible? Is this a good idea or is there a better practice ...
2
votes
1answer
26 views

Postgis spatial query st_disjoint

I have 2 layers that I want to compare. I wish to retrieve the features in the layer 1 that have no part in common with the features in the layer 2. I try queries like that but do not returns me the ...
0
votes
0answers
24 views

How to convert a geojson from Postgresql to geojson format readable in rCharts in R?

I am creating a Rshiny interface on that can take in user input and SELECT the respectively map layer from Postgresql database based on the input. The package I am using to plot the map is rCharts. ...
0
votes
0answers
10 views

Finding Census Tracts Within a Circle in PostGIS [duplicate]

I suspect this is a basic question but, for a newb like me, it's proving to be quite a challenge. I have imported (using ogr2ogr) a collection of census tracts from the U.S. Census-provided .shp files ...
0
votes
0answers
11 views

In PostGIS, is it possible to use `ST_SnapToGrid` align to a coordinate system?

I am wondering if it is possible to align a raster or geometry by specifying the coordinate system using the spatial reference identifier, i.e. 4326 for WGS 84. I did not see anything in the ...
0
votes
1answer
21 views

PGR_Djikstra function error

I'm trying to find a shortest path between 2 nodes using djikstra method but it keeps saying ERROR: Error, query must return columns 'id', 'source', 'target' and 'cost' this is my query: ...
0
votes
1answer
28 views

Align pixels from two rasters with different cell sizes

I have two rasters in a PostGIS database that I want to be able to compare. The first raster is at 5m pixel resolution and the second raster is at 30m pixel resolution and is on a different grid. How ...
0
votes
0answers
19 views

How to remove lines made with a PostGIS query automatically if origin is not in the map window?

I have a PostGIS point layer with labels. I moved these points because they were too close. To connect label and point, I created a line vector layer which was made with a query in the DB-Manager ...
0
votes
0answers
5 views

Install PostGIS without Internet Connection [migrated]

Hi I have binaries but am working on a machine that is on a network not connected to the internet, and I need to install and run PostGIS without Stack Builder or an internet connection. I've tried ...
1
vote
0answers
24 views

Creating quadtree index on latitude, longitude data in PostGIS

I have a table of locations in which one of the columns represents the lat-long for the location. These coordinates have been extracted from the OpenStreetMap file. How can I create a quadtree index ...
0
votes
0answers
31 views

Windshaft + Postgres to read geojson

I am using Windshaft and trying to figure out how I can take a geojson text object from Postgres and have it rendered as a tile layer. I have tried the following query: sql: "select ...
0
votes
0answers
24 views

Up-dating postgis spatial table from CSV files

I have a PostGIS Table I produced from importing a layer file itself created from a CSV. I am getting updates to the main file through other CSV files and need a method of importing the new CSV's into ...
0
votes
2answers
44 views

Hardware Requirements ? Overpowered?

I'm running a i3 3,1 GHz Machine, 4 GB of RAM with an onboard Graphic Chip. I build a small GIS with Mapbender3, Geoserver based on PostGIS data. It's running pretty fluid from what i can see. Now i ...
0
votes
0answers
29 views

Web Application for display raster data on basis of time slider

It May act as a duplicate question to many, but i have tried refering too all the questions related to my questions, but i am still confiused. Below in attached my code. which i use for Web Mapping ...
1
vote
1answer
32 views

What can I use to generate an interconnected graph from a series of coordinates?

I have a table containing latitude and longitude coordinates, and I'd like to be able to build an interconnected graph from it to use with pgRouting. Is there an existing feature of postGIS or ...
0
votes
1answer
52 views

Import point cloud into PostgreSQL/ pdal pipeline fails

I have a point cloud dataset that I would like to upload to my postgres/postgis database. I followed this tutorial and I could install everything without problems (on ubuntu 14.04. On ubuntu 12.04 ...
0
votes
0answers
10 views

Unable to Display Postgis Database Table Geometry Column Points in Geomoose

I'm a beginner in this field.I want to plot the postgis database table geometry column in geomoose but it is showing a pink tile.Through an android device we are pushing latitude and longitude to ...
0
votes
1answer
31 views

postGIS st_equals function not working as expected

I have a situation where I need to find out if a geometry being imported into a postGIS 2.1 database matches one drawn previously (i.e we want to know if the imported geometry is less up-to-date than ...
0
votes
1answer
21 views

How does ST_SnapToGrid work using nearest neighbor interpolation?

I have rasters in a PostGIS database that are not necessarily aligned (some rasters offset from the grid). I want to use ST_SnapToGrid to align all rasters to the same grid but have some questions ...
1
vote
0answers
18 views

How does `ST_Union` treat NULL values in a raster?

My question is about how ST_Union of rasters containing NULL values are handled. For example suppose I have two rasters that intersect but the values of the intersection are NULL in one of the ...
0
votes
0answers
34 views

Densifying OpenStreetMap (OSM) network nodes?

I am working with osmconverter to convert osm files(*.osm) to *.pbf, then i use osm2po to get sql file that run into PostGis to get a network table. The last step is to run a createTopology ...
3
votes
1answer
72 views

How to create an exact tracking route from GPS data with animated icon?

Probably this is not purely GIS related question, its related to developing issues. I am just asking if there is any kind of suggestions from Gurus. I am building an tracking application where GPS ...
3
votes
2answers
53 views

Remove specific points from linestring postgis

I am working with a data set that has been using the (0 0) point to pad any points that were missing when the linestring was created. So now the query SELECT id, route as line FROM trips ...
0
votes
0answers
22 views

pg_dump Database that was populated with osm2pgsql

Is it possible to dump a postgres database that was created with osm2pgsql and a .osm.pbf file with pg_dump and import this into a remote postgres database? After running osm2pgsql the database is ...
1
vote
0answers
60 views

Help serializing a postGIS query to geojson

I have a query which I would like to serialize to geoJSON: select article_title, pub_date, city, geom from article, location where article.id = location.id; I can serialize the geom field easily ...
0
votes
1answer
49 views

Check if point is inside unclosed linestring using POSTGIS ST Functions [closed]

I have a table with spatial data. This table contains a single record which is a unclosed linestring. I calculated the Centroid of this geometry using query SELECT ST_AsText(ST_Centroid("geom")) ...
0
votes
1answer
31 views

Converting spatial data to table of vertices using PostGIS?

I have a spatial data table in PostGIS 2.1 that looks like this: Geom | type | cost POLYGON(0 0,1 1,2 2)| A | 123 POLYGON(3 3,4 4,5 5)| b | 123 I am trying to create a ...
7
votes
1answer
118 views

How fast should I expect PostGIS to geocode well-formatted addresses?

How fast should I expect PostGIS to geocode well-formatted addresses? I've installed PostgreSQL 9.3.7 and PostGIS 2.1.7, loaded the nation data and all states data but have found geocoding to be much ...
0
votes
1answer
29 views

Utilizing OSM Data in a Postgres/PostGIS database in ArcMap

I've been trying for over a week now, and I'm not sure what i'm doing wrong and I haven't found the answer yet. I am trying to display and symbolize the OSM dataset over Jordan in ArcGIS for Desktop ...
3
votes
1answer
56 views

How to change the “application_name” of a PostGIS-connection in QGIS?

PostGIS offers a view called pg_stat_activity, where you can see all the active connections to the database. This view includes the interesting column application_name. When a connection comes from a ...
1
vote
1answer
40 views

How to create regular point grid inside a polygon in Postgis without knowing cell size but cell number?

I need to create a grid within a polygon like it is done in How to create regular point grid inside a polygon in Postgis? There a function is created to draw the grid points. But necessary to know ...
0
votes
1answer
34 views

QGIS DB Manager - load as new layer not loading

After successfully running an SQL query on two tables and some results in 3 columns, I would really like to be able to display it in the canvas. Apparently, that function is not doing anything, not ...
1
vote
1answer
36 views

PostGIS 3D bounding box query that envolves all 3 axes (xyz)

I have some experience with PostgreSQL, but not with PostGIS, and for the life of me I can't make my bounding box take the Z axis into account. I have a points table with XYZ columns. I add another ...
1
vote
1answer
72 views

Number of Neighbors Around a Point

I need to get a count of neighbors within 100m for each point in a set of 250 million points. The result would have the id of each point accompanied by the number of neighbors around them. Can this be ...
1
vote
1answer
28 views

Best way to filter points given a starting point and max travel time

I have a database of about 1M geolocated addresses and I'm looking for a way to sort/filter these records based on a starting point and max travel time. Ex: "find every baker shop within 30 min ...
0
votes
0answers
24 views

Merging DEM files using PostGIS

I have several DEM files and I want to merge them to create a mosaic. I found the St_Union(raster) or St_MemUnion(raster) functions but I don't know how to use them. Are there any other solutions?
0
votes
1answer
90 views

How do I explode a MultiLineString using ST_Dump() in PostGIS?

I want to do what this blog post does: explode a MultiLineString into individual LineStrings. I'm using CartoDB but don't get individual LineStrings as the result of my query. I still get a ...
1
vote
0answers
35 views

OSM Bright Cartography XML

So I've successfully setup a tile server as described here: https://switch2osm.org/serving-tiles/manually-building-a-tile-server-14-04/ What's troubling is the lack of clarify surrounding OSM Bright ...
0
votes
0answers
16 views

polygonize some raster pixels based on their value in PostGIS

I need to extract and polygonize only those pixels of a raster that have a value (e.g.) greather than 2000.0 The reason is that I wish to do an operation like the following one (which is done only on ...
0
votes
0answers
40 views

Use QGIS and Qt dialog forms

I have a QGIS project where there are plots with a attributes like name of the owner, address of the owner, cultivate, and so on. This plots are read from a PostGIS database. The future users of this ...
0
votes
1answer
24 views

Using virtual or temporary geometry with PostGIS and pgRouting

I am attempting to find the shortest/fastest routes from GPS point to GPS point as described in this post: Create closest point on multilinestring to use in shortest_path() I have seen many solutions ...
1
vote
0answers
24 views

Displaying multiple features from a geoserver layer with time and style in a KML

I have 4 datasets organized in a PostGIS database each of the same geometry and location except they are at different times. They each have a corresponding datetime field. I can load these into a ...
1
vote
0answers
17 views

Selecting all pixels above a given value in a raster in PostGIS

I have a raster with one band whose value represents the date of the occurrence (a sequential integer). This raster file gets updated regularly, and each time that happens, I need to run a process ...
1
vote
0answers
64 views

Rendering TopoJSON in Leaflet from GeoJSON PostGIS output?

I'm using the query found here SQL query to have a complete geojson feature from PostGIS to get a geojson that I can display on a leaflet map. However, the amount of data is kinda big and the ...
0
votes
0answers
47 views

OL3 doesn't display the wms Layer

This is pretty much related to the question asked in the following link How to add Mapserver WMS to Openlayers 3 I followed the example in ...
1
vote
0answers
23 views

Merge raster tiles in PostGIS

I have several raster tiles that are adjacent and non-overlapping, so they form a mosaic. I am trying to merge two adjacent rasters using PostGIS but am getting an error that they do not have the same ...
0
votes
1answer
22 views

Reprojection not generating properly the tiles

I am executing this query with cartodb.js. I am moving the markers radomnly to generate a new layer. cartodb.createLayer(map, { user_name: 'mickemr', type: 'cartodb', sublayers: ...
3
votes
1answer
42 views

Postgis query on 3D cube does not use index

I am testing Postgis on the follow query: SELECT * FROM particles WHERE position &&& 'LINESTRING(0.08537 0.0738 0.0145,0.0953 0.0837 0.0345)'; that returns about 100k rows from a ...