In a geodatabase, a mechanism for optimizing access to data based on the spatial column of the business table.
4
votes
3answers
117 views
Trying to combine nearby points into a polygon
We have collected millions of cell phone strength readings. I am trying to group points of the same strenght that are within a distance of each other in to a polygon. I asked on the
postgis mailing ...
0
votes
0answers
24 views
Spatialite, to speed performance, when should I create Views, Indexes or additional spatial tables?
I’ve got a large Spatialite database with a table of lines (roads, rail and water). I created a spatial index of the geometry to speed things up.
This works amazingly well when I’m zoomed in ...
3
votes
0answers
59 views
Creating a ShapeFile spatial index programmatically in .Net
I am creating a shapefile programmatically using DotSpatial using the following example syntax / pseudo code
FeatureSet features = new FeatureSet(DotSpatial.Topology.FeatureType.Polygon);
...
4
votes
3answers
282 views
Create Spatial Index in PostGIS on an entire Schema
I have loaded a number of shapefiles using SPIT (QGIS plugin) to my PostGIS database. These layers did not have a Spatial Index created upon loading. I am wondering if there is a way to create a ...
4
votes
1answer
155 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 ...
7
votes
3answers
2k views
Poor Performance when using Spatial Indexes in MySQL
Re-post of a question asked on Stack Overflow when it was suggested this would be a better forum.
I'm trying a little experiment at pushing a data set which is not geo-spatial but fits it quite well ...
2
votes
1answer
91 views
Why doesn't PostGIS use gist index when doing a ST_DUMP(ST_UNION)?
My query:
DROP TABLE IF EXISTS tmp;
CREATE TEMP TABLE tmp AS SELECT *, ST_BUFFER(the_geom::GEOGRAPHY, 3000)::GEOMETRY AS buffer FROM af_modis_master LIMIT 20000;
CREATE INDEX idx_tmp_the_geom ON tmp ...
2
votes
1answer
279 views
rtree python polygon index
Sorry for a very basic questions about rtree.
I would like to check whether the point is inside the polygon and the distance (point to the nearest point in polygon) as well. I was thinking about ...
8
votes
3answers
249 views
How to speed up queries for raster databases?
I have a raster database in postgresql/postgis with these columns:
(ID, rast, data_of_data).
'rast' is the column that has raster files in WKT format. An example query to find the DN value of a ...
2
votes
2answers
161 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 ...
8
votes
2answers
362 views
PostGIS Intermittent INDEX Performance
I have a table containing approximately 55 million data points ( point is a geometry with SRID 4326 ) and for my query I need to join this to an area table ( currently have ~1800 areas ) which ...
2
votes
2answers
342 views
Is ArcMap 10.0 Query Layer passing invalid SQL to Oracle 11gR2?
In two different environments I'm having trouble using ArcMap 10.0 Query Layers to view SDO_GEOMETRY (point) data in Oracle 11.2. This suggests I'm doing something wrong...
Points are in Oracle ...
1
vote
3answers
184 views
how to create RTree index on LineString geometry
I'm working with NTS(NetTopologySuite), then I get some geometries with type of LineString, and I want to create the IntervalRTree Index on them.
Here are some codes:
...
2
votes
2answers
161 views
IFeatureIndex2.Index Performance Issues ArcObjects
I have a large number of polygon features in a personal geodatabase featureclass. I would like to find the nearest polygon for several points inside an area of interest(the red area in figure).
I ...
1
vote
0answers
112 views
How could I make this PostGIS query run faster?
SELECT st_band(rast, 1), st_width(rast), st_height(rast),
st_bandpixeltype(rast, 1), st_bandnodatavalue(rast, 1),
st_scalex(rast), st_scaley(rast), st_upperleftx(rast),
st_upperlefty(rast) FROM ...
17
votes
2answers
1k views
Acquiring ArcGIS-like speed in Postgis
I have been using Postgis 2.0 for 3/4 of a year now and while I really enjoy using it, excessive query processing time has rendered it basically unusable for my use case.
I tend to do heavy ...
2
votes
1answer
265 views
SQL Server 2008 Spatial Index Nearest Neighbour
I am trying to query geopoints for nearest neighbour, Whether I use spatial index or not, I always get similar times and it takes about 6 seconds. How can I speed this query up?
Here is my query:
...
10
votes
3answers
881 views
optimize nearest neighbor query on 70 million extremely high density spatial point cloud on SQL Server 2008
I have about 75 million records in a SQL Server 2008 R2 Express database. Each is a lat long corresponding to some value. The table has geography column. I am trying to find one nearest neighbor for a ...
3
votes
1answer
362 views
Shorter Version of this SpatiaLite Query
I've been doing some spatial queries using spatialite, and they're large enough that a spatial index becomes a must. An example of using an index is given in the tutorial
spatialite> SELECT ...
11
votes
4answers
1k views
Speeding up OpenStreetMap PostGIS querying
I have OpenStreetMap data for the Netherlands loaded into a PostGIS database (PostgreSQL 8.3 / PostGIS 1.3.3) using the osmosis schema. This means all tags are stored in a hstore field. In addition to ...
3
votes
2answers
289 views
Spatial Indexes on OS MasterMap Data
What are the optimal settings for setting up a SQL Server 2008 Spatial database with full UK OS MasterMap data in?
Seperate tables for the different feature types, or a single table with everything ...
3
votes
2answers
1k views
How can I use R-Tree to find points within a distance in Spatialite?
Create a table with 3D points:
create table points (coords pointz);
select CreateSpatialIndex('points', 'coords');
Insert 13k rows:
insert into points values (geometryfromtext('pointz(...)'))
Do
...
3
votes
1answer
981 views
How do I create a functional spatial index of an ST_Geometry Feature Class in Oracle/SDE?
Copied an SDE feature class (with blob(sdebinary(?) geom) into the same SDE GDB (Oracle 11g/SDE 9.3.1) but with the ST_geometry configuration keyword. I can see that the feature class was created, ...
4
votes
3answers
2k views
How to properly utilize DWITHIN Spatial Filter in OpenLayers
Given the following code:
var points = [];
points.push(new OpenLayers.Geometry.Point(-110, 38));
points.push(new OpenLayers.Geometry.Point(-108, 40));
var lineString = ...
4
votes
1answer
155 views
Spatial index vs two coordinates indexes
I have a table with two columns: latitude and longitude. I want to get all objects inside a "rectangular" (well, rectangular in a lat/lon coordinate metric) bounding box: min-max latitude and min-max ...
1
vote
3answers
705 views
C# library for bounds based geometry search
I am searching for C# library which has code that builds spatial index in memory based on geometry bounds and enables fast searching for all geometry inside given bounds.
I prefer free library.
2
votes
2answers
362 views
How to delete a broken index in SpatiaLite?
I managed to screw up an index in my SpatiaLite database. The index was created using spatialite-gui. In the meantime, I deleted the original table and three out of four index files: ...
4
votes
2answers
521 views
How does a quad-tree cope with very large objects?
If I use a quad-tree to index my map data, how does it cope with a road that goes from one end of the map to the other?
What other sort of indexes should I consider to get round this problem?
