Tagged Questions
0
votes
1answer
49 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 ...
2
votes
0answers
67 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
49 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 = ...
3
votes
1answer
922 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 ...
0
votes
1answer
74 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 ...
3
votes
1answer
109 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
186 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
359 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
199 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
124 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
225 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
129 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
220 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 ...
6
votes
3answers
161 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 ...
4
votes
1answer
653 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 ...
