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

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Pointers to open source C/C++ code for converting Lat/Lon data into geo-spatial indices in a triangular or hexagonal grid?

I have a streaming data application which needs equal area geo-spatial indexing of input Lat/Lon observational data for locality of referencing. From reading, it would seem that a triangular or ...
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4answers
101 views

Postgis don't use spacial-index with st_intersects

I imported the data from openstreetmap using osm2pgsql and copied it another table structure. If I made a query for containing rows using st_intersects, st_contain or someone else, postgis don't use ...
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3answers
126 views

How to efficiently access the features returned by QgsSpatialIndex?

The PyQGIS Cookbook explains how to set up the spatial index but it only explains half of its usage: create spatial index — the following code creates an empty index index = QgsSpatialIndex() ...
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1answer
49 views

Basic sp-gist indexing?

Please forgive a very, very elementary question. I am using a PostgreSQL 9.3.5 database, and one of the tables stores longitude and latitude. (These are two separate columns.) I would like to do ...
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36 views

Silly problem with spatial index?

I explain : I've got a points layer in .shp, it's allright, no problem with display( pan, zoom it's ok)… But when I create a spatial index, display of the map becomes crazy. It's not easy to explain ...
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211 views

PostGIS doesn't use index for spatial query

I can't get PostGIS 2.1 running on PostgreSQL 9.3.5 to use a spatial index even for the simplest queries. The whole dataset is 8 million points (population count grid from here ...
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1answer
40 views

Index to speed up ST_HausdorffDistance?

When comparing similarity of linestrings with ST_HausdorffDistance (or another type of similarity function), is there a way to use an index to speed up the search for similar linestrings?
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31 views

How to create my own remote sensing index?

Using Landsat images how do I create my own indices to extract particular landuse? Are there any tool/ software for creating indices?
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223 views

Understanding the Use of Spatial Indexes

I'm having trouble understanding the use of spatial indexes with RTree. Example: I have 300 buffered points, and I need to know each buffer's intersection area with a polygon shapefile. The polygon ...
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40 views

Match housenumbers on buildings (special case of point-in-polygon-test)

Task with example I'm working with geodata (country-size) from openstreetmap. Buildings are often polygons without housenumbers and a single point with the housenumber is placed within the polygon of ...
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1answer
120 views

Spatial search performance on a collection of Points in a PostGis database

Let's assume you have a huge PostGis spatial table (using Postgresql 9.2, postgis 1.5) : BIGTABLE ( p Point, someData varchar ) which contains millions of records. Each record has been created ...
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1answer
63 views

What are the PostGIS Raster Constraints used for?

My question is quite basic, but I have not found a simple explanation of why raster constraints are useful. I have worked with rasters in PostGIS for a while but only recently I realized that I do ...
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111 views

Geoserver WFS features query inaccurate using SQL Server Backend with spatial index

I´m using Geoserver to query features through WFS in an Web Application with Openlayers as client. The queried layer is using SQL Server as backend storage. When applying a spatial index to the ...
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1answer
593 views

Fastest strategy for proximity searches in SQL Server 2012

This is my very first question here, so bear with me! I'm implementing a back end for a mobile app which will have to do proximity searches to find nearby POIs (points os interest). I know it's a ...
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1answer
91 views

How to quickly extend PostGIS's R-Tree implementation?

I am working on a problem where along with data points location, I also have information about the connectivity between points.(Think a graph of points, where an edge denotes some relationship) My ...
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28 views

Cannot see shapes in ArcCatalog or ArcMap after creating spatial indexes? [closed]

I created a spatial index on a feature class, but when I try to load it in ArcMap, I cannot see the shapes. When I remove the spatial index, I can see the shapes in ArcMap/ArcCatalog.
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1answer
90 views

Does QGIS automatically use spatialite spatial indexes?

When you write a query in spatialite you have to manually join your query to the spatial index for that index to be used to speed up the query. When QGIS displays data does it take advantage of any ...
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2answers
74 views

Geary's index of spatial autocorrelation

Does anyone knows If there is a way to calculate Geary's index of spatial autocorrelation on open source gis?
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2answers
127 views

Does PostGIS have separate implementation of GiST index from PostgreSQL?

I want to know if PostGIS has a separate implementation of GIST index or it reuses the GIST index implementation provided by Postgresql?
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1answer
399 views

How do you build a MongoDB spatial index for GeoJSON geometry?

I'm attempting to build a spatial index on a collection of features that I created from: ogr2ogr -f GeoJSON out.json ... and then imported into MongoDB (2.6.1). When I attempt to build a spatial ...
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1answer
69 views

PostGIS Spatial Index not used after copying table

I am copying a PostGIS database from my computer to our webserver. I always had problems to copy the entire database using pg_dump and pg_restore so I am creating a new database on the server and copy ...
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47 views

How to serialize a HTML form to GeoJSON data?

I'm developing a Cordova/PhoneGap mobile application and using NodeJS for server and MongoDB as database. I need to serialize GPS data from mobile phone to send it to my webservice with latitude and ...
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1answer
283 views

create polygon adjacency matrix using python

I am trying to create an adjacency matrix from a set of polygons. That is, I have a bunch of polygons and I want to identify which polygons have a common edge or "touch" each other. Once I find this ...
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218 views

Are there trade offs between using a geohash vs using a quadkey as a spatial index?

QuadKey Bing Maps uses a quadkey structure for their tiling scheme. Here is an overview of the concept http://msdn.microsoft.com/en-us/library/bb259689.aspx. GeoHash A geohash seems to be the more ...
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70 views

mongoDB query not working as expected

My mongoDB collection has all three types of shapes. A point is stored as { 'CE_NO': '_', 'E_NAME': 'RAILWAY BOOKING CENTER', 'SRCTYPE': 'Facility', 'geom': { 'coordinates': [ ...
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216 views

sql server spatial index performance

I have a table with around 2 million records in it. I create a spatial index, using the defaults other than the bounding box. I've been noticing that some queries are extremely fast, and some are ...
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1answer
316 views

ST_Intersects() in WHERE clause misses results

I have a table with a lot of geographical objects like countries, cities or points inside the cities. For instance # SELECT id, ST_AsText(location) FROM brace_brace WHERE id IN (3, 42); id | ...
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1answer
241 views

Is it possible to use JTS for calculations on data in geographic coordinates?

I have some spatial data that has all of its coordinates as lat/lon pairs (with about 10 digits decimal precision), it's stored in a database as WGS84 data. Some of the data is represented as polygons ...
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430 views

How do you view the current spatial index grid size for a file geodatabase feature class?

I am receiving an "The spatial index grid size is invalid." error during a copy/paste of polygon features in ArcMap and I successfully corrected it with AddSpatialIndex. But in an effort to figure out ...
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1answer
482 views

Is it possible that a good spatial index just cannot be made?

I have about 6 million rows with geography spatial features - they are all 1000 meter radius hexagons all over the US. There are a couple hundred thousand that would have been NULL, which I updated ...
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1answer
56 views

Is there a way to force ArcCatalog to use a specific tessellation scheme for a SQL Server spatial index?

If I Recalculate a spatial index from ArcCatalog, the tessellation scheme is always set to "Geometry Grid". Even when the previous index was Geometry auto grid. ArcCatalog always changes it back. ...
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2answers
270 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 ...
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1answer
224 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 ...
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497 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 ...
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1answer
474 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
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1answer
234 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 ...
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52 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 ...
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2answers
322 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 ...
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210 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 ...
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241 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 ...
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299 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); ...
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1answer
996 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 ...
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1answer
292 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 ...
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3answers
434 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 ...
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3answers
1k 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 ...
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1answer
897 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 ...
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1k 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 ...
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558 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 ...
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2answers
905 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 ...
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716 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: ...