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

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3
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1answer
50 views

GIST slows down query?

I have an odd case where creating a GIST index slows down my query instead of speeding it up. The setup consists of two tables, one with multi-polygons, another with points. I want to calculate which ...
0
votes
2answers
31 views

Building efficient multi geometry type database with PostGIS?

I'm trying to build a PostGIS database which must be able to store (multi)points, (multi)linestrings and (multi)polygons. The goal is to efficiently querying the data with ST_Intersects and other ...
2
votes
0answers
86 views

display issue in qgis 2.14 : features appear and disappear

I have several virtual layers in my project. One of them contains 6 lines. Depending of the scale, at least one line disappears from the canvas for an unknown reason. I heard that sometimes, creating ...
0
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0answers
34 views

What is the impact of changing grid sizes while applying spatial index on specified table in SQL Server 2014

I have a Feature class with millions of points of interest (contains OID and geometry columns) which is stored in ArcSDE along with other non-spatial datatables which are stored in SQL Server DB . I ...
1
vote
1answer
46 views

Using Postgis spatial index in st_distance operation based upon explicit SRID column

I have two large tables with data that spans over multiple regions of the U.S and needs a defined SRID column in atleast one the tables to denote which coordinate system should be used for ...
2
votes
1answer
70 views

Bulk loading into pyrtree index

I'm using pyrtree to create an index for a point in polygon operation. I am currently trying to insert 1.8 million rows into the index and it takes more than an hour to do so. I am unable to use rtree ...
2
votes
2answers
75 views

Postgis Functional Index on st_pointonsurface() Ignored

If I define the following table... CREATE TABLE tbl_vast_importance( id bigserial PRIMARY KEY, geom geometry(MultiPolygon,4326) ); CREATE INDEX ON tbl_vast_importance USING GIST (geom); CREATE ...
2
votes
1answer
74 views

Running Gevel on PostGIS 2.0

I have found Gevel, a tool enabling the visualization of the content of the GiST indices in Postgres. In particular, I am interested to use it to visualize the RTree spatial index in PostGIS. Does it ...
8
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0answers
82 views

Accessing the internal data structure storing Postgis spatial index (PostGres GiST)

I am curious about how the internal data structures and storage mechanism of the spatial GiST index in Postgis. In Oracle, I used to like to show how the SDO indexes were "just another table", and how ...
2
votes
0answers
16 views

PyQgis - How to update a spatial index?

I am trying to speed up a QGIS plugin I wrote by adding a spatial index to a vector layer. The aim of my plugin is to simplify a line network by merging some of its features, based on some criteria. ...
3
votes
0answers
50 views

QgsSpatialIndex partial or complete overlap

I'm working on adding some functonality to a QGIS plugin. It currently uses a QgsSpatialIndex to efficiently compute whether the features of a vector layer intersect (potentially millions) of ...
0
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0answers
36 views

“Spatial index is to small” from same geodatabase

I have an interesting thing going on. I have an ESRI geodatabase which contains numerous (versioned) featuredatasets. When I export for example a featureclass to a shapefile and try to import the ...
2
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0answers
38 views

In memory spatial index for frequent updating point objects

Is there any in memory spatial index specialized for frequent updating point objects? The dataset will be moving cars, most likely update per second but with millions of them. The project will be ...
1
vote
0answers
18 views

Spatialite Index not matching

I have a dataset containing GPS points I store in a table with a geometry column. I use the following code to populate my table. CREATE TABLE STOPS_GEO ( stop_id TEXT PRIMARY KEY, stop_desc TEXT, ...
1
vote
1answer
48 views

nearest N objects (points) [closed]

i'm searching nearest ten neighbor points from a given point. When i use this query: SELECT id, geom, ST_Distance(geography(geom), ST_GeographyFromText('SRID=4326;POINT(-0.22707 51.5444204)')) as ...
2
votes
1answer
36 views

Indexing PostGIS table by tile boundaries

I have a PostGIS table with 2M rows, all Points. I'm creating tiles from the data, but it's quite slow. Although I have the normal geometry indexes enabled on the table, I wonder if it's possible to ...
0
votes
0answers
117 views

how to use spatial index in spatialite query

I posted this question originally nearest neighbor query in SpatiaLite. Thanks to the answer given I was able to get the query working on some test data. However I am having trouble applying a spatial ...
1
vote
0answers
188 views

Using a ShapeFile spatial index with ogr2ogr and ogr.DataSource.ExecuteSQL()

I created a spatial index foo.qix for a foo.shp with ogrinfo -sql "CREATE SPATIAL INDEX ON foo" foo.shp However, when I do a query with ogr2ogr and look at it in strace, it doesn't use that index: ...
2
votes
1answer
92 views

OpenStreetMap Data Lookup Slow in PostGIS

I have imported OpenStreetMap data (Europe) into PostgreSQL 9.1 database with the help of osm2pgsql and filtered out everything expect administrative areas. I have GIST index for polygon (way) column. ...
0
votes
1answer
64 views

Problem with spatial index PostGis

I'm using Postgis 2.1. I have this table with about 50k rows: CREATE TABLE rilevazioni ( geom geometry(Polygon), stimolo integer, tmstmp timestamp without time zone, id bigserial NOT NULL, ...
1
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1answer
81 views

ArcSDE PostgreSQL configuration parameters for Spatial Index?

I wonder why there is not any configuration parameter (DEFAULT Keyword) for spatial indexes in Arcsde for postgres. In ArcSDE for Oracle we have S_STORAGE,S_INDEX_SP_FID,S_INDEX_ALL parameter for ...
0
votes
1answer
274 views

How to disable spatial index creation by ArcSDE for Oracle Spatial

Working with arcsde 10.1 and oracle spatial 11g. I set the feature class in load_only_io before loading shape files. I am using geoprocessing tool (append) in arcgis to load shape file to ...
2
votes
4answers
672 views

PostGIS doesn't use spatial 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 ...
4
votes
3answers
2k 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() ...
2
votes
1answer
259 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 ...
1
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0answers
82 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 ...
6
votes
1answer
576 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 ...
1
vote
1answer
58 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?
0
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1answer
47 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?
5
votes
2answers
981 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 ...
2
votes
0answers
58 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 ...
0
votes
1answer
243 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 ...
5
votes
1answer
217 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 ...
1
vote
1answer
254 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 ...
5
votes
1answer
4k 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 ...
3
votes
1answer
233 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 ...
4
votes
1answer
199 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 ...
2
votes
2answers
198 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?
3
votes
2answers
307 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?
2
votes
1answer
823 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 ...
1
vote
1answer
83 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 ...
3
votes
2answers
794 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 ...
7
votes
1answer
490 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 ...
1
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0answers
188 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': [ ...
4
votes
0answers
360 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 ...
2
votes
1answer
532 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 | ...
0
votes
1answer
399 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 ...
2
votes
0answers
1k 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 ...
6
votes
1answer
1k 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 ...
0
votes
1answer
96 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. ...