0
votes
3answers
45 views

postgis insert query to store geometry and other data

I'm using Postgis functions st_dump and st_split to split a polygon based on line. Now, after splitting; output geometry stores in a database table as well. Here is the query: insert into aoo(geom) ...
0
votes
0answers
26 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 ...
11
votes
0answers
246 views

How to query OSM for all beaches facing west? - QGIS preferred

I want to identify all beaches on this planet (or a given subset of it) that are facing westwards (+/- 20-30 degrees). My idea is to use OSM as the data source. Extracting all polygons that have the ...
1
vote
2answers
123 views

Searching planet_osm_point by longitude and latitude

I used osm2pgsql to import data into my PostgreSQL database and it put gave me the following 4 tables, planet_osm_point, planet_osm_line, planet_osm_polygon and planet_osm_roads. I have looked at ...
1
vote
1answer
58 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 ...
0
votes
0answers
34 views

display route from database(postgresql) on

For first part: Link i have postgresql9.1,postgis2,pgrouting2 and qgis2.2 this is the second part of what i need to do: Search in a database (postgresql with pgrouting) for a line from public ...
-1
votes
1answer
132 views

Shortest Path Dijkstra

I would like to calculate the shortest path with dijkstra algorithm. sample query SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_dijkstra(' SELECT gid AS id, ...
0
votes
1answer
80 views

How to cut/split multipolygon with blade (linestring) into two pieces using PostGIS? [closed]

I struggle to do split operation in postgis I tried to build a query but Im always fail. Id like to cut a multipoligon with a blade (a linestring) into two pieces. These two objects have specific ...
3
votes
1answer
322 views

PostGIS intersection function

I have a problem with intersection function. I built my query following http://manual.linfiniti.com/en/postgis/geometry.html, 5.7 section. I made my clip object, a red linestring frame: But after ...
0
votes
2answers
54 views

Select area which is at least x meters away from other geometries

In my table I have the build-up area from a region as a big number of polygons. urban_area: id | name | geometry(polygon) I was wondering if and how I would be able to find the area within a ...
0
votes
1answer
108 views

Defining a WHERE clause from a subquery for a query to create a handy view

It is about my implementation from an answer of this question. It is more an postgresql issue than a GIS issue, whereas it is about geometries and spatial queries. I want to create a view from the ...
0
votes
1answer
275 views

PHP/MySQL, PostgreSQL spatial queries. Find a polygon that contains a coordinate? [closed]

I am building a non mapping javascript app and I am wanting to take a lat/long coordinate and query a MySQL table of polygons for the one that contains the point. I have looked into MySQL spatial ...
1
vote
1answer
113 views

Computing altitude from contour table - slow ST_Dwithin query

I am using PostgreSQL 9.2/PostGIS 2.0. I have a table of house addresses and a table of contour lines which are as follows: address_list house_id | geom (point, 4283) ---------+--------- 1 | ...
5
votes
4answers
100 views

uDig window to change between historical dates?

I'm new to uDig, but I'm experienced Java developer. I have points with temperature measurements that change overtime in SQL database. I would like to give user ability to change between historical ...
1
vote
0answers
72 views

PostGis search query on hstore tags

I am writing a search client, to query postgis db. The search query will be, SELECT tags->'name' AS name,ST_Transform(way,4326) AS pt_lonlattext FROM planet_osm_point WHERE lower(tags->'name') ...
0
votes
1answer
76 views

How to select all cities in Germany from city and country layer?

I have 2 layers: layer_1: countries of europe, layer_2: cities of europe I want to create (and then save) a layer_3 which would be all the cities of Germany. Is there any good tutorial of how can i ...
3
votes
0answers
247 views

Select features within a country or bounding box effectively using PostGIS

I imported the planet OSM file into a PostgreSQL 9.2/PostGIS 1.5 server using osm2pgsql. I now want to select certain map features which lie within the bounding box formed by a countries borders, e.g. ...
0
votes
2answers
179 views

PostGIS, distance between two users

I have a simple table (location_test) with three column (name, geom , jid). geom is a geometry column with SRID 27700. I set the user's geometry position with: UPDATE location_test SET geom = ...
0
votes
1answer
107 views

In QGIS can I show just the lines in a Postgis query? How can I do that?

I have three tables in Postgresql, each table with one layer of lines. I want to show the path of an initial line to another final. Is it possible executing a SQL query? Thanks My three tables are ...
4
votes
1answer
671 views

How to Find points in a Kilometre radius

I am new to PostGIS and GeoData. I need to find where the lightning has stroke by a period of time and kilometre radius based on a given location. I have given lon/lat and my table is: latitude ...
4
votes
1answer
532 views

How to speed up an st_intersects() query?

I have a "huge" spatial database: 72GB, 200 millions documents with geometries (points) I have a GIST index on the geometries the database: CREATE TABLE resources ( id bigint NOT NULL, accuracy ...
4
votes
3answers
1k views

How to join two tables using date, time, lat and lon as common field?

I am sorry if the question is elementary but I did not find any clear discussion or guide to understand how to run a query in postgresql. So that a pointer to another website would be also useful. ...
5
votes
2answers
692 views

PostgreSql query problem with aggregate functions

I need help with a PostgreSql query. I need to find all parcels which have bigger area then average. I'm using this query: SELECT OBJECTID FROM parcela WHERE ST_Area(geom)<(SELECT ...
2
votes
1answer
200 views

How to filter or query data in GRASS?

I have a PostGIS dataset with just over 2 million rows. Each row has a PostGIS geometry point value and several attributes. I'd like to do some analysis on certain subsets of the data, but I can't ...
2
votes
2answers
888 views

Spatial index to speed up the query

I have spatial table in PostgreSQL 9.2 / postgis 2.0 that I have to extract some information from it. But my query is hopelessly slow. How could I make use of spatial index to improve the performance ...
3
votes
2answers
152 views

Multiple queries in a row

I have osm data imported into PostgreSQL with osm2po tool (wich makes the data routable). Also I have imported data relationed with nodes and node_tags with osmosis tool. I need to obtain a set of ...
4
votes
1answer
305 views

Improve database performance for geospatial

I have a database with osm data imported with osmosis tool. I want to search for the nearest POIs from a given point. For this purpose, I perform this query: select id from nodes where ...
4
votes
1answer
1k views

How to find the nearest point by using PostGIS function?

table A: lat | long | the_geom | code | sign 13.8433095 | 100.6360357 | 0101000020E61.... | ABC | start_point 13.7544738 | 100.5459646 | 0101000020E6..... | ABC | end_point 13.4124215 | 100.6232332 ...
8
votes
3answers
352 views

How to select only Spatial tables from the postgres database?

My database contains both Spatial and Non-Spatial tables, but I want to retrieve only Spatial table from the query. Any suggestions to select only Spatial tables. 'the_geom' is the geometry column in ...
5
votes
1answer
2k views

How do I perform a proximity search with Postgis?

OK, so I downloaded the Geonames database (cities1000) and wrote a small Ruby program to import them into my table (geo_cities). I then added geography column called geog. So after all of that, I ...
3
votes
3answers
3k views

How to fix performance problem in PostGIS ST_Intersects?

I'm a newbie in postgis and I have a problem in query performance. This my query: SELECT DISTINCT ON (userid) userid ,ST_AsText(position), timestamp FROM table1 WHERE ST_Intersects ( ...
2
votes
1answer
2k views

Basic MapServer query of PostgreSQL/PostGIS database

I've just installed MapServer on a linux server and I am trying to understand how to display a basic map using a PostGIS database. I have displayed a shapefile in the browser, so I know that the ...
11
votes
1answer
547 views

Nearest Neighbor Grouped Selection in QGIS

OK - so I have an interesting problem I am trying to solve. I have a list containing over 100,000 points in lat/long format which I have imported into qgis. Now, what I am trying to do here is group ...
0
votes
2answers
976 views

QGis import partial PostGIS layer using query builder

I'm sorry, but I'm terribly new to the GIS scene (and PostGIS & QGis). I have loaded a whole bunch of OpenStreetMap data into a PostGIS database and successfully drawn a map using Mapnik. Now I ...