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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2
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1answer
35 views

Query Geopackage using spatial index in QGIS DB manager

I would like to do spatial join in QGIS DB manager on geopackage database. The query should look like this select * from Soil_C_cadaster a, (select * from Soil_C_cadaster where forest_c is null) b ...
2
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1answer
140 views

Index to speed up similarity comparison when all the lines are along a same x-axis?

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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44 views

PostGIS query to retrieve geometry that intersects both a bbox intersects and also matches other columns

I am relatively new to GIS, so have been searching around to try find a similar case to the one I am facing but have come up short. Specifically I want to store multiple sets of geometry features in ...
3
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1answer
126 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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0answers
30 views

How to average the NDDI index for a map in GEE

In previous codes I was able to generate the NDVI average, but since NDDI is a sub-index I would like to know if anyone would be able to generate this NDDI average in GEE https://code.earthengine....
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1answer
1k 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
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1answer
32 views

SQL Server how to create spatial index? ( spatial query )

I know how to do spatial query, Shape is my geometry type column. bbox is well know text format of a bounding box srid = 2229, you must specify this srid in where intersect clause ...
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0answers
37 views

Raster Calculator conditions in QGIS [duplicate]

I'm trying to create an index using the Sentinel Imagens at Raster Calculater (QGIS), but I don't know how to put the following conditions: if ((B2>B3) and (B3<B4) and (B4>B11) and (B4>...
2
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1answer
107 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
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1answer
180 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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1answer
174 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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0answers
25 views

PyQGIS how to construct QgsSpatialIndex with FlagStoreFeatureGeometries flag?

In the PyQGIS documentation for QgsSpatialIndex.nearestNeighbor (https://qgis.org/pyqgis/master/core/QgsSpatialIndex.html#qgis.core.QgsSpatialIndex.nearestNeighbor) we see the following (!) Warning: ...
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1answer
104 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 ...
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1answer
37 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 ...
2
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1answer
395 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 ...
3
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1answer
151 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, ...
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2answers
1k views

Creating Spatial Index for Geopackage using QGIS?

Working in QGIS 2.18.14 standalone on Windows, is there a way to create a Spatial Index for Geopackage (gpkg) layers?
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0answers
49 views

High cost of geometry bitmap heap scan

I have a PostGIS database with tables osm_admin (with contains all administrative boundaries from osm data) and osm_landusages (with contains all landuse areas form osm - like forests, industrial/...
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0answers
84 views

geometry point and varchar multicolumn index in PostgreSQL

Is it possible to create a multicolumn index on a geometry point column and a varchar column? For example, say I have a geometry point column called "location_point" and a varchar column called "zip". ...
4
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1answer
47 views

Spatial index not used in view which union several tables

I have multiple spatial tables each of which I have created gist index, and query for each table will cost 10-200ms as shown in the following example, the spatial index can be used. Example 1(with ...
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0answers
32 views

How to get index of specific location in IDL

I am trying to get the index of specific lat and lon in IDL. I know how to do it in python. tmp = tmp.sel(lat=lat_loc,lon=lon_loc,method='nearest') But I can't find a way to do so in IDL. Any ...
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0answers
435 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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0answers
262 views

Defining partial or complete overlap with QgsSpatialIndex

I'm working on adding some functionality to a QGIS plugin. It currently uses a QgsSpatialIndex to efficiently compute whether the features of a vector layer intersect (potentially millions) of ...
2
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0answers
69 views

PostGIS runs out of memory due to the use of spatial index

I am running this query on PostgreSQL. CREATE TABLE table3 AS (SELECT t1.id FROM table1 AS t1 CROSS JOIN LATERAL (SELECT t2.geometry AS geom_closest FROM ...
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0answers
121 views

Speed up PostGIS raster query

I have a simple PostGIS table as follows: \d rad; Table "public.rad" Column | Type | Collation | Nullable | Default ...
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0answers
69 views

Spatial index not speeding up spatialite query containing Multipoint Geometry Data?

I am querying a sqlite format geodatabase in which there is a label for each geometry shape. Think of data as : label = name of a district in your state geometry: polygon which specify the ...
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0answers
285 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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0answers
54 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&...
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0answers
439 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 ...
6
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2answers
466 views

Building spatialindex in Postgres with JNDI for GeoNetwork?

Which steps should be taken to build the spatialindex table inside PostgreSQL when using a JNDI connection? Is the table built by GeoNetwork or does it need to be created manually? What I have ...
1
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1answer
120 views

GIST index not used by query optimizer on geometry field

I'm trying to add elevation curves on an OpenStreetMap tile server I'm currently building. I created a table in PostgreSQL to store the shapes of the whole world. Structure was defined by gdal_contour ...
2
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1answer
217 views

postgis: scaling / optimization of shortest distance between two geometries (seeking recommendations)

I have two tables in postgis: one with 1B rows containing points (POINT, 4326)::geometry the other, with 250k rows containing linestrings also in 4326 Both tables have a GIST index. I am trying to ...
7
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0answers
147 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 ...
2
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0answers
148 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
46 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. ...
3
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1answer
463 views

Spatial Index on 100s of Millions of Records Taking Days in PostGIS? [closed]

I have a table with ~200million spatial records in it, and it is taking days to build a spatial index on the one geometry column: should this be taking so long? The geom column is of the type ...
0
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2answers
90 views

Creating index file in FME 2018?

Is there a transformer to create a index file for my shapefile output? As a .qix file on QGIS.
1
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1answer
47 views

QgsfeatureRequest - Store result indexes

I recently posted a question. My original goal was to find a way to determine on which side of a line points are located. @xulnik answered this question with two codes. One returns a binary [0;1] ...
2
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0answers
370 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-...
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1answer
154 views

Chronological sort & indexing problems with QGIS Time Manager

I am trying to use QGIS Time Manager to create an animated map of property connected to polygon-geometry. The one article on animating polygons I've found on this site hasn't helped because my data is ...
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0answers
354 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 ...
3
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2answers
273 views

Query slowed down by gist-index on points

So I have this simple query, selecting all points in my table that are within a given polygon: WITH my_polygon as ( SELECT ST_GeomFromEWKT('<EWKT polygon>') as geom ) SELECT count(*) FROM ...
2
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3answers
4k 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.
6
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2answers
385 views

Geometry distance PostGIS query with <-> operator suddenly much slower

One of my websites suddenly got much slower, and I've managed to track down the issue to a query that uses the <-> operator together with ORDER BY (2D distance between two geometries) to ...
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0answers
141 views

Which approach is faster for getting all POIs from MySQL/MariaDB with PHP/Laravel [closed]

Correct me if I'm wrong. There are three approaches to get the nearest homes, users have created in my website: To create a table with two columns(latitude, longitude) that both of them are float ...
5
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1answer
220 views

QgsSpatialIndex.nearestNeigbor() unexpected result

I have a Linestring layer for which I have build a QgsSpatialIndex with the following code: my_linestrings_lyr_idx = QgsSpatialindex() for f in my_linetraings_lyr.getFeatures(): ...
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0answers
297 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 ...
6
votes
1answer
318 views

3D time dimension (x,y,t) [closed]

I'm working with data points (x,y) and timestamp t as a separate attribute in my table. (x, y) are in WGS 84 latitude,longitude format while timestamp is in Unix Time. For instance (71.8, -13.5) and ...
3
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0answers
249 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 ...
0
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1answer
809 views

Errors in creating spatial index on SDO_GEOMETRY column in Oracle 11g

I am using Oracle 11g (Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production) and I have a table that has column of type SDO_GEOMETRY. I want to create a spatial index on this ...