Questions tagged [performance]

Performance concerns how effectively a computing system uses resources.

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0answers
103 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 ...
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1answer
140 views

Speeding up ArcGIS Desktop, arcpy code

Each time I run the a code, see below, the ArcGIS window updates the results and the process is extremely slow. Is there a way to let python know that it doesnot have to update the results each time ...
0
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1answer
396 views

QGIS 2.18.10 getting slower after 3 months?

I'm currently reporting an issue our users are facing in the field. We are using QGIS / PostgreSQL to collect data on daily basis and since few weeks they are noticing a huge difference in ...
2
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4answers
423 views

Handling large datasets with Erase/Dissolve in ArcGIS (Dissolve alternative?)

I have what should be a simple problem: erase a large multipart polygon layer from a larger polygon (see below for example). However, I believe the Arc Erase tool is trying to erase each part of the ...
2
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1answer
72 views

Why does it take longer and longer to export my maps as png in a loop?

And how can I improve my performance? I wrote a simple python script to export a few hundred maps: Open a MXD, add a layer, apply a definition query, apply a symbology, export to PNG. The definition ...
1
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2answers
218 views

Uploading table (shape) to asset using Google Earth Engine? [closed]

I am trying to upload a table (shape) to my assets and it has been uploading for 7 days. Is it normal? I do not understand why spends so many time.
3
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1answer
425 views

Choosing data source when serving vector tiles from GeoServer?

I am about to set up a basemap with some 20-30 layers, served as a group layer in GeoServer. Output format is pbf vector tiles. Should I stick with postgis or shapefiles if I want best possible ...
1
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1answer
224 views

Improving poor performance of ArcPy update cursor with ArcSDE and Editor? [closed]

I am using ArcGIS 10.5 in an ArcSDE environment. I have two tables, they are the exact same table schemas, but one is being edited and those edits are being pushed to the main table. I am a little ...
6
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1answer
183 views

ArcPy script runs longer processing time in scheduled task than in ModelBuilder?

I have a Python script that runs ArcPy and a model that is imported with a Toolbox. When directly running the model on ArcMap, it takes 4 plus minutes. It takes about the same time if running in the ...
2
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1answer
168 views

GDALDEM hillshading running slow?

I have, for a while, been trying to make a terrain map using NASA's SRTM 3 dataset. I have a large (13 GB), geotiff projected to web mercator of all the elevation files provided. I have been able to ...
3
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2answers
431 views

intersection in postgis takes hours and hours to run, why?

I have a table with approximately 500,000 records that I am trying to intersect with a table that has about 30,000 records. It was running for 11 hours until I finally stopped it. Why would this ...
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1answer
70 views

how can i speed up GRASS i.segment?

I'm trying to find a way for speeding up the segmetation process, it's using little resources (7% memory), and I think I can give it a little more core or memory to speed it up, I already set the ...
2
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1answer
214 views

GeoServer: which library for boosting (raster) WMS output generation [closed]

I have a GeoServer instance, which is only used as a WMS service. Reading the docs, there are libraries, which can be used to boost WMS ouput generation: native JAI and ImageIO JAI-EXT libjpeg-turbo ...
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2answers
138 views

How is arcpy.Clip_analysis() so fast against non-arcpy implementations?

I'm using a version of Solution 2 of the selected answer here to build a new shapefile of all points that fall within a given polygon object (i.e. a clip). When run against 27K points, it takes ...
0
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1answer
4k views

Leaflet vs Mapbox GL JS: JavaScript libraries comparison

I would like to do a comparison of Leaflet.js and Mapbox GL.js libraries. Therefore I would like to ask if you have some ideas of which parameters should I test. In my initial research I decided to ...
8
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2answers
2k views

Displaying huge geotiffs (or vrts) with QGIS?

I am manipulating and processing global rasters at 30m resolution. The total raster sizes are usually [1,440,000 560,000]. I have access to a supercomputer, so I have written code that allows me to ...
1
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1answer
332 views

Geoserver shape simplification performance

So, while wondering about shape simplification in the eternal struggle for optimization, I find out (here on SE) that Geoserver and PostGIS can and will (by default) perform the trick on the fly (see ...
1
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1answer
123 views

copy value if an attribute comparison match with another layers attribute is found in PyQGIS

Unfortunately, the two layers don't cover the same size of area and therefore don't have the same number of attributes. That's the reason I only saw the following attempt, instead of simply zip them. ...
2
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1answer
137 views

Tile rendering time measurement in MapServer?

I try to speed up rendering time of tiles in mapserver app. How can I specify rendering engine in mapserver? The only thing about I found is: outputformat Tiles are generating very slow - about 4-5 ...
4
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2answers
564 views

Alias for postgis function is really slow

I have created an alias for st_expand function like this CREATE OR REPLACE FUNCTION expand( geom geometry, value double precision) RETURNS geometry AS $BODY$ DECLARE my_geom geometry; BEGIN ...
3
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1answer
71 views

Why does my RAM cap out around 150 MB when doing the Distance Matrix analysis in QGIS?

I am currently trying to determine the 2 nearest points for a database of 8 million people against 425 locations. I have 2 csv files uploaded into QGIS one with a unique number for 8 million people ...
6
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1answer
712 views

LineString VS Multi-LineString Performance PostGIS

Our road dataset (14mil segments, 300,000+ km length) is in Multi-LineString, I am thinking about shifting it all to LineString since all the roads in our data are single geometries and multi part ...
3
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1answer
182 views

Convert DEM elevation points from centimeters to meters

I would like to convert a large DEM stored in PostGIS which contains elevation values in centimeters to elevation in meters. I found an easy way by updating each point like this: UPDATE mydem a SET ...
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0answers
245 views

Esri ST_Geometry functions too slow on Oracle

I'm writing an SQL statement to create a feature class and using st_geometry functions. But it's taking too long. So I begin the statement with a join, which is taking 150-200ms SELECT PRC.OBJECTID ...
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0answers
257 views

Osm2pgsql importing speed not improving when using a SSD?

I have built my own OSM server and I am trying now to import UK into my Postgis database using osm2pgsql. I have changed the data directory of the database (succesfully) and I have mounted a Samsung ...
2
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0answers
145 views

Faster equivalent of arcpy distanceTo method

Unfortunately arcpy distanceTo method is painfully slow. When speed is crucial, I am still using Avenue to work around it, but it is getting harder to transfer ArcView 3 to newer computers. As ...
0
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1answer
448 views

PostGIS Geocode function taking a lot of time some address, but not others

I setup a PostGIS/Tiger database and have been going through trying to optimize my queries. At this point I have am having issues with geocoding certain addresses, and I just can't seem figure it out. ...
2
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1answer
37 views

Speeding up a Query

I am using PostGIS/Tiger and I would like to find all locations within ~2 miles (~3218 meters) of a given location. The location in question is obtained by just doing select geography(the_geom) FROM ...
5
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1answer
524 views

Why is QGIS points in polygon so slow when select is fast?

I'm looking at QGIS 2.18.9 and using a polygon to select points from a large point layer (file based tab file). I wondered why the process is so slow if you use plugins or analysis options? I ask ...
2
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1answer
220 views

geoJSON feature stack problem in OL3

I'm using code from geom's answer at Is there an easy way to use Postgis GeoJSON in Openlayers 3 to load PostGIS layers into my OL3 map application. Each time I pan/zoom far enough to trigger a ...
2
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1answer
753 views

Selecting features by attribute in QgsVectorLayer faster?

I've gone through many posts here that describe some ways of selecting features by attribute, but there is really no definitive answers as to which way is the fastest way of selecting features from a ...
6
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1answer
622 views

Speeding up Leaflet with GeoJSON data app?

I am working on a Leaflet app which will be displaying five layers with about 1k points each. For our purpose (basically in order to locate most of the points near to a road) we don't want to use ...
2
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0answers
111 views

Understanding why arcpy.CreateScratchName() gets slower with more file geodatabases in folder?

In my ArcGIS Pro 1.4.1 application, I noticed that a short section of ArcPy code that creates a scratch name, and then uses that to create a file geodatabase (always in the same folder with the same ...
0
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0answers
79 views

ENVI Mosaic Speed

I have several Sentinel-1 images to mosaic. The first mosaic is for 2 images of land area removal. The size of mosaic result is about 4.8 G, the second mosaic result is also about 4.8 G. Then to make ...
1
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1answer
234 views

Fastest closest points datastorage

I have pretty large dataset (>10M records) with a geography points (id, latitude and longitude), and need to find closest points from this set. Data itself is not updated very often but I need quick ...
4
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0answers
388 views

Why my Geoserver on JBOSS/RHEL is slower than on Tomcat/Windows?

I have my Geoservers in 2 different environments: Tomcat on Windows and JBOSS on RHEL. I was guessing that JBOSS on RHEL will be faster, but to make sure I made some test plans with JMeter. Both: ...
3
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0answers
79 views

Scaling postgresSQL database when searching polygons against points?

I am using our single server - CentOS 6.6 x64 16 CPU 24 GB SSD (PostgreSQL) 9.4.1 as our GIS database processing engine. This is part of the PostGIS software package installed on the server. I am ...
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0answers
266 views

2D visualisation Benchmarking for QGIS?

I've just started working as a GIS technician in a land agency firm. I'm handling large datasets such as historic house sales (~500,000 rows of data per year) and executing heavy duty operations, sub-...
2
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0answers
123 views

ArcMap basemap layers take a long time to display [duplicate]

Over the years I've often used two of the available ArcMap basemap layers (Imagery and USA Topo Maps) as part of my work. I've noticed that ArcMap consistently takes 10-15 seconds for the screen to ...
2
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1answer
480 views

Why is a ST_Union within same table slow - shouldn't it be instant?

I'm working in Postgres 9.6. I have a table that looks like this: gid | integer | not null default nextval('usgovt_gid_seq'::regclass) category | character varying(12) ...
3
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1answer
1k views

Speeding up intersect query in PostGIS?

I would like to count the number of points that intersect with a list of polygons. The polygons are very complex (county/state boundaries). I'm using this query: SELECT gid, county_name, (...
0
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1answer
198 views

Why is ArcPy script looping through bands slow?

I am working on a single tiff with over 20k bands, each representing daily temperature, and I'll be extracting and preforming simple raster math on roughly 3500 of the bands. The problem I'm running ...
1
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1answer
127 views

Deleting Feature Classes Faster

I have a script that runs through a database and deletes all the empty feature classes. Often I deal with databases that have hundreds of empty feature classes and it can take quite a while to run ...
0
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1answer
2k views

How to speed up Google Geocoding API Slow performance?

I am using Google geocoding API service with their Java client, and my dev Key, The problem is when I run up to 40 requests it does slow to 600ms. I am using it in a webservice that is supposed to ...
0
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2answers
184 views

Changing MXD Reference using ArcPy?

On one of our projects, I have been creating .mxd Files that reference a PostgreSQL Database. For some corporate reasons, the database had to be relocated to a new server, leaving all the mxd ...
7
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2answers
1k views

Open layers supercluster integration - is it possible to fetch underlying features for each cluster?

I am using the open layers 3 with supercluster at the moment, extending the example provided here : https://jsfiddle.net/d5gwvz2y/2/ My question is: How does one fetch all the underlying features ...
1
vote
1answer
138 views

Using Search/Update Cursor?

I am trying to get field values from one table and use them to perform calculations on a row in another fc table. Does anyone have any ideas on how to make this run faster? I've tried a dictionary ...
1
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0answers
1k views

Way processing is too slow in osm2pgsql? [duplicate]

I'm importing the planet data file. After see the Node processing taking about a hour at 2800.0 k/s to finish I think all job will be fast but now Way is still working after 28 hours at 0.5 k/s and ...
1
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0answers
117 views

Quickest Way to Calculate Land Area by Grid Cell in PostGIS

I have a grid vector table that covers the entire world and want to calculate the land area within each grid cell using another table that contains a single polygon for all continents. I tried the ...
2
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2answers
994 views

Geoserver extremely slow performance on Raspberry pi model 3b

I have a postGIS database and tomcat8 with Geoserver installed in my raspberry pi model 3b running Ubuntu MATE. The problem is, geoserver runs really slow, and I mean really slow. It takes up to 15 ...