Questions tagged [spatial-index]

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

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193 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 ...
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65 views

Calculate volume of space defined by multiple overlapping 3D polygons

I have thousands of 3D polygons scattered in space but they mostly overlap with many of their neighbors in big extent. Is there any way how to compute volume they define effectively? I would love ...
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240 views

When does a QGIS .qix spatial index of a shapefile need to be re-created?

I understand the basics of spatial indexes but would like to understand when exactly a spatial index would need to be re-created or updated? The reason I ask is because when a folder was moved to a ...
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93 views

Speed up identify in QGIS

I have just transferred my Postgis database onto an RDS server, and there is a bit of a performance hit when using the Identify tool in QGIS (3) compared to localhost. I presume this is mostly network ...
4
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755 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); features....
3
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1answer
122 views

Getting the largest rectangle in the R-tree index of a PostGIS table?

Is it possible to use SQL or PL/pgsql to get the largest rectangle in the R-tree index (or other types of indices) of a table, so that it can be used as Bounding box for PostGIS table? If possible, ...
3
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176 views

Geoserver ImageMosaic ignores existing datastore.properties (connect to PostGIS) and automatically generates index using shapefile

I am new to Geoserver. I am trying to publish a WMS service for a raster time series using the ImageMosaic plugin in Geoserver. I am using the sample dataset and instructions at this link I want to ...
3
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95 views

Most performant KNN method in postgis (<->, <<->>, st_distance)

My question is about the fastest way to order query results by approximate distance. I've seen conflicting information about this. My data are lat/lng points stored using WGS84 (SRID 4326). The ...
3
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221 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
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1answer
120 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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2k 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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202 views

SP-GiST for geography type in PostGIS

This CREATE INDEX geography_gdx ON schema.table USING GIST (geog); works, but CREATE INDEX geography_gdx ON schema.table USING SPGIST (geog); gives me [42704] ERROR: data type geography has no ...
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216 views

Optimizing MySQL query to select all points with in a large polygon using spatial indexes

Re-posting it from stackoverflow as per their suggestion. Link to the thread in stackoverflow https://stackoverflow.com/questions/53182385/optimizing-mysql-query-to-select-all-points-with-in-polygon-...
2
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1answer
170 views

QGIS3 Creating spatial index in a standalone script as a part of output vector layer

I am making a buffer analisys in a standalone script. Is it possible to automatically during the analisys add index to the output vector layer (".qix" file)? I tried to add after the analisys like in ...
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292 views

Improve the speed for ST_DWithin

I need to get the outer polygon of the LSOAs within 10 miles of each postcode centroid. There are 180k LSOA polygons in table1 and 2.6 million postcode centroid points in table2. I have created 2 ...
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96 views

Adding Spatial Index for Geometric Network?

I am trying to create Spatial Indexes on all the feature classes in one of my databases. It has worked fine on most feature classes so far, but when I started on feature classes in a feature dataset ...
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0answers
202 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 ...
2
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1answer
97 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 ...
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752 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: ...
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307 views

Destroying spatial index using PyQGIS?

QGIS 1.9 Is it possible to destroy a spatial index? I am noticing that if I generate a spatial index on a set of polylines (within a plugin), split one of the lines, and then recreate the spatial ...
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314 views

GeoDjango and spatial indexes

I have three questions about spatial indexes management in GeoDjango, and I can't find the answers in the documentation. First, I know GeoDjango creates a spatial_index for a geometry field by ...
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340 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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716 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 close....
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276 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 public....
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33 views

Multiprocess Spatial Join with Spatial Index

I'm a newbie in implementing GIS on Python, but the lack of any GIS software at the office has forced me to learn about it. I have a huge grid (a multipolygon) that I'm currently filling out with ...
1
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1answer
28 views

Finding Rows Inside other Rows

So I have database with which I want to do the following: Find out which other rows are contained within the geometry of the row in question. To keep it simple, I am finding the envelope/bbox of the ...
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45 views

PostGIS: Is it interesting to create an index on geom column and an alpha numeric field?

I would like to know if it's interesting to create an index on an other column than the geom one. In some cases, I would like to do spatial analysis. If not, I would like to analyse only attributes. ...
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211 views

QGIS does not seem to make use of spatial index when using GeoPackages

I have a QGIS project with several Geopackage-Layers. The project is quite slow in comparison to a project with shapefile or database layers. I started QGIS together with DebugView to find out what ...
1
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1answer
128 views

Distance between point and line layers & spatial index issue

I am trying to compute on QGIS the distance from some clusters (ie points) to their closest road (ie lines); no need for all combinations, just the distance from each cluster to the closest road. To ...
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195 views

When I should use Rtree/KdTree vs Morton z-index and s-curves?

I was always confused by those two families (?) of indexing. I feel that the first one goes with the "normal" data, while z-index and s-curves work the best for tiling/grid/uniformly distributed ...
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61 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, ...
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597 views

Using spatial index in spatialite query?

I posted this question originally Using nearest neighbor query in SpatiaLite? Using the answer given I was able to get the query working on some test data. However I am having trouble applying a ...
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97 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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45 views

Spatial index for a raster column in a table in PostGIS

I have a raster table in PostGIS. When I run ST_SetValue(rast, geom , value) on it to change the pixel value at a point, it works very slowly. Do you know how can I create spatial index for a raster ...
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39 views

Transfer indexed Oracle geoloc table to PostgreSQL using ogr2ogr

I am copying tables using ogr2ogr from Oracle to PostGIS using ogr2ogr -f "PostgreSQL" PG:"host=<host> port=5432 user=<user> dbname=<dbname> password=<pwd>" OCI:<USERNAME&...
0
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1answer
44 views

Export NDVI values from chart as JSON in Google Earth Engine

After filter OLI8 for a small area var collectionFilter = ee.ImageCollection('LANDSAT/LC08/C01/T1_RT_TOA') .filterBounds(geometry) .filterMetadata('CLOUD_COVER','less_than',4) .map(app); print(...
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91 views

NetworkX - Indexed Spatial node queries?

I'm trying to extract a Road Network from a large set of GPS point data gathered from vehicles. I plan on representing the final network in terms of a NetworkX graph of G(V,E) I have implemented ...
0
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137 views

Storing a Spatial Index in Sqlite

I would like to store an r-tree or quadtree index in a sqlite database using python. Does anyone know if there is any code to do this? A bit of background: The dataset cannot be moved to another ...
0
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0answers
32 views

How to Drop Indexes on a Table in ArcCatalog

I am using an Oracle 11g database . The code below doesnt allow me to drop indexes on a table. import arcpy # Remove indexes and statistics for gis feature class delta tables COND=r'E:/...