In a database, a mechanism for optimizing access to data based on the spatial column(s) of a data table.

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2
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2answers
558 views

How to work with the STRtree Index when object in the index change it's position?

I'm work with the NTS(NetTopologySuite), I get large amounts of Point geometries, for fast querying the point object, I make the STRtree Index like this, STRtree tree = new STRtree(); foreach (var p ...
2
votes
1answer
406 views

Fast zipcode detection from latitude/longitude

I need a way to get the zipcode of a lat/long pair fast (<10 ms), and at a high rate (thousands of qps) I've loaded a shapefile from the US Census Bureau into a mysql database with spatial ...
1
vote
2answers
859 views

How to speed up spatialite-query using spatialindex?

I have got 2 tables, one of type LineLayer called strlayer, the other one is a PolygonLayer called blayer. The LineLayer contains two rows called fromBland and toBland that should be filled with an ...
4
votes
1answer
851 views

For which operations a PostGIS Geography index is useful?

I need to do KNN- and within-region queries for POI data. I store the POI locations in a geography column. Since I understand that ST_DISTANCE doesn't use the geography index, I added a geometry index ...
2
votes
2answers
399 views

3D KNN index in PostGIS

I am looking for a way to do fast KNN queries on a dataset of 10+ million 3D points (and growing). I was hoping PostGIS would do the trick with its new <-> and <#> operators, but they don't seem ...
1
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0answers
73 views

Indexing GIS data associated with user with timestamp

I have data for each user in this format user1:(timestamp,lattitude,longitude) user1:(timestamp1,lattitude1,longitude1)..... Here the 1 at the end of timestamp/lat/long is to specify a different ...
7
votes
2answers
405 views

Basics about Spatial Indexes

I was asking on a forum if it could be a good idea to create spatial indexes on subsets of a table when your application display on map only those subsets and never the entire table. I was asking ...
1
vote
0answers
268 views

Adding multiple layers to Tilemill from a single sqlite DB

This is a repost of a question I had over at the MapBox support board. Since I wasn't having much luck over there, I'm hoping I would have better success here. I'm having trouble adding more than a ...
0
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0answers
389 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 ...
4
votes
0answers
455 views

Creating 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); ...
5
votes
2answers
2k 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 ...
2
votes
1answer
441 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 ...
5
votes
3answers
576 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 ...
11
votes
3answers
2k 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
1answer
2k 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 ...
3
votes
3answers
2k 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
679 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
1k 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 ...
2
votes
3answers
1k 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
355 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 ...
2
votes
0answers
216 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 ...
4
votes
1answer
2k 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: ...
46
votes
2answers
7k 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 ...
4
votes
3answers
2k 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
2answers
4k 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 ...
4
votes
2answers
474 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 ...
5
votes
1answer
437 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
2k 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.
4
votes
1answer
597 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 ...
12
votes
3answers
2k views

Optimize nearest neighbor query on 70 million 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
2k 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
3k 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 = ...
11
votes
5answers
3k 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 ...
9
votes
3answers
4k 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 ...
4
votes
2answers
870 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: ...
6
votes
2answers
841 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?