Questions tagged [performance]
Performance concerns how effectively a computing system uses resources.
742
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Creating Vector Polygons with rendering performance like GISCloud?
I have been looking for a solid solution which would allow me to create a web map and overlay vector polygons without taking forever to load such data with the goal of allowing me to make each polygon ...
- 2,310
47
votes
7
answers
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Tuning PostGIS for production environments
What PostGIS documentation have you come across that has been helpful when tuning PostGIS for a production environment?
I would like to get together with my DBA to setup a Postgresql/PostGIS ...
45
votes
3
answers
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Performing bounding box query in PostGIS?
I have a PostgreSQL table, with almost 2 million rows, with a long-lat coordinates field in the form POINT(-73.4938 33.2405).
Supposing there's a geospatial index on that field, what's the most ...
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39
votes
4
answers
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Performance of ArcGISScripting and large spatial data sets
I am currently writing a python script using the arcgisscripting module to process a reasonably large data set (~10,000 records in total) normalised over a small number of tables, 8 in total. The ...
- 2,359
39
votes
6
answers
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Increasing speed of crop, mask, & extract raster by many polygons in R?
I'm extracting the area and percent cover of different land use types from a raster based on several thousand polygon boundaries. I've found that the extract function works much faster if I iterate ...
- 1,177
38
votes
2
answers
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Fastest way to count the number of features in a feature class?
With the introduction of the Data Access module in arcpy (30x faster search cursors), I want to know if counting features matching sql criteria is faster than the traditional MakeTableView + GetCount ...
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26
votes
4
answers
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How can I optimize pgrouting for speed?
I am using pgrouting on a postgis database created through osm2pgrouting. It performs very good on a limited dataset (3.5k ways, all shortest path A* searches < 20 ms).
However since I have ...
- 1,565
25
votes
3
answers
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Speeding up plotting of polygons in R
I want to plot the country borders of North America over a raster image depicting some variable and then overlay contours on top of the plot using R. I have been successful in doing this using base ...
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21
votes
7
answers
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How to improve rendering performance of a very large shapefile?
I have a polygon shapefile that has a 100MB .dbf, and 500MB .shp file component. The reason it is so large, is that it is classified as a landbase for a whole district.
Everytime I view the file in ...
- 574
19
votes
2
answers
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How is the data access cursor performance so enhanced compared to previous versions?
The data access module was introduced with ArcGIS version 10.1. ESRI describes the data access module as follows (source):
The data access module, arcpy.da, is a Python module for working with
...
- 51.5k
18
votes
4
answers
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Fastest way to convert big raster to polyline using R or Python?
I have a big raster file (129600 by 64800 pixel) with global water bodies (1 bit values 0 and 1) and try to extract ocean and inland water shorelines.
I've tried with ArcGIS and QGIS to convert from ...
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3
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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 ...
- 541
17
votes
6
answers
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Why is the performance speed between ArcGIS and QGIS so different?
Ok I am not a programmer but a prolific GIS user. I know that QGIS is written in C++ and ArcGIS in ??? but for most of my tasks lately I always try to use QGIS not only because it is free but due to ...
- 1,233
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votes
2
answers
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PostgreSQL/PostGIS spatial index - no speed up
I have a spatial table in a PostgreSQL/PostGIS database. Every row in it represents a Polygon. It is of following form:
+----+--------+
|gid | way |
+----+--------+
|241 | 01030..|
The geometric ...
- 263
16
votes
3
answers
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Performing GIS benchmarks?
I was searching the web for benchmarks (but couldn't find any) that would indicate hardware performance (probably cpu in particular) in different GIS software in time consuming tasks (like hillshade ...
- 5,097
16
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1
answer
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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 ...
- 261
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votes
1
answer
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How many ArcGIS for Server service instances is optimal?
What is the best number of ArcGIS for Server instances?
When I increase the number of instances will the services run faster?
- 1,529
15
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3
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Selecting ArcSDE polygon by point in ArcGIS Desktop using ArcPy?
I keep thinking that I must be missing something, but there does not seem to be a tool in ArcGIS 10 to select features (in particular polygons) from a layer at a point (X,Y) location via ArcPy. The ...
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14
votes
4
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Does a large amount of GPU memory help when working with very large images and image mosaics? [closed]
It seems like it would help a great deal to store as much of the image as possible on the GPU for panning and zooming, etc.
We deal with a lot of very large images. Many range from 8 GB to hundreds ...
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votes
5
answers
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Looping through 16 million records using ArcPy?
I have a table with 8 columns and ~16.7 million records. I need to run a set of if-else equations on the columns. I've written a script using UpdateCursor module, but after a few million records it ...
- 419
14
votes
1
answer
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Counting overlapping polygons in PostGIS using ST_Union very slow?
I have a set of 1000 polygons that overlap and I want to count the areas of overlap. I am using this blog post's instructions to create multilines from the 1000 polygons then use this line file to ...
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votes
3
answers
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Increasing display performance of ArcGIS Online Basemaps like Bing in ArcMap?
I'd like to know if there are ways (within ArcGIS itself) to increase the display performance of basemaps within ArcMap. The internet connection was recently upgraded, so it is much faster than before,...
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1
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Understanding why ArcPy Cost Path Analysis tool faster than ArcObjects? [closed]
Although I use python to create geoprocessing scripts/services, I was under the impression that using ArcObjects to do the equivalent operation(s) will have better performance.
I've posted ArcGIS ...
- 5,705
13
votes
3
answers
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Poor Performance when using Spatial Indexes in MySQL
Re-post of a question asked on Stack Overflow when it was suggested this would be a better forum.
I'm trying a little experiment at pushing a data set which is not geo-spatial but fits it quite well ...
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13
votes
1
answer
3k
views
Why do simple joins on small datasets slow down ArcMap so badly?
ArcGIS 9.3.1, ArcInfo. I have some small file geodatabase and SDE featureclasses (few thousand records each, 50 columns) that I am doing attribute joins on. After the joins, drawing of the map is ...
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13
votes
2
answers
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Lots of layers in one or multiple services? (and why)
Scenario:
Client has a web mapping application. Does not want to split into multiple smaller applications. Although this goes against what the modern day approach is for maps on the web, (i.e. ...
- 9,858
12
votes
2
answers
3k
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Why is ArcPy script slow?
I have a simple arcpy script to update a field in a point shapefile with info from the polygon feature that it is within. It takes 9 minutes to do 100 points in arcpy but a spatial join in arcmap is ...
- 290
12
votes
4
answers
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How many layers are too many layers in ArcMap?
I work on ArcGIS using a Citrix virtual software connection at work. It is dreadfully slow at times, and without any changes to the MXDs I'm working on, one minute ArcMap can be operating at a ...
12
votes
5
answers
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Compiling Python scripts (to .exe) that use ArcGIS Geoprocessing Tools?
I've been coding with Python for several months now and have developed some reasonably complex scripts for primarily geoprocessing tasks. That being said, I'm still learning a lot as I'm coming from a ...
- 1,127
12
votes
6
answers
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Does using RAM Disk improve ArcGIS Desktop performance appreciably?
I configured a RAM disk on a Virtual PC running ArcGIS Desktop 10 and set my HKCU\Software\ESRI\Output\TempPath to a directory on the RAM disk. It’s hard to perceive any sort improvement with that ...
- 14.6k
12
votes
3
answers
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Measuring performance difference between Merge and Append in ArcGIS Desktop?
Often I find myself in a situation where I don't care whether or not my tool produces a new feature class, but I do care how long it takes to combine all of my large datasets. Does it take longer to ...
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12
votes
2
answers
798
views
QGIS form performance
Edit: tl;dr
QGis apparently casts my primary key on postgresql to text when using the identify tool. This causes the form to be slow in startup because it disregards the index on it. A (tested) quick ...
- 1,327
12
votes
4
answers
10k
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Fixing performance problem in PostGIS ST_Intersects
I am new to PostGIS and I have a problem in query performance.
This my query:
SELECT DISTINCT ON (userid) userid ,ST_AsText(position), timestamp
FROM table1
WHERE ST_Intersects ( ST_GeomFromText('...
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12
votes
2
answers
4k
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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 ...
- 2,884
12
votes
6
answers
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Slow loading of QGIS Project
I have a number of standard projects set up for QGIS users. Some of them take more than 5 minutes to load. Things recently got much worse suddenly - and I want to track down why.
Are there any methods ...
- 2,982
12
votes
2
answers
6k
views
Shapely with Rtree versus STRtree
I have a huge interrogation regarding the performance difference between Rtree and STRtree included in Shapely. Below is a short code where we create randomly 250 000 triangles (defined by 4 vertice) ...
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11
votes
4
answers
10k
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QGIS rendering performance bottleneck?
When I load a vector with a large number of features into QGIS, the rendering time can become extremely slow. But when I look at my system resources, they all have plenty of excess capacity.
What is ...
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4
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Performance of ArcGIS Engine using multiple file geodatabases as opposed to one?
I'm trying to decide the best way to organize my data for an ArcGIS Engine application. I am particularly interested in map display and query speed. Currently I have all of my data separated into ...
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votes
3
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Which data format typically displays fastest in ArcMap?
My organization is working on an application running on ArcGIS Engine. Previous versions of the application used primarily Shapefiles for displaying roads, parcels, buildings, etc.
Since I was ...
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11
votes
3
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Using Label classes vs Definition queries - which performs the best?
Which would provide the best performance for working within ArcMap with very large datasets stored in an ArcSDE geodatabase? Multiple label classes using complex SQL queries to label specific features,...
- 9,131
11
votes
1
answer
587
views
Python Script Performance as an ArcGIS Tool Versus Stand-Alone
Has anyone studied the difference in running a Python script in ArcToolbox versus as a stand-alone script? I had to write a quick-and-dirty script to convert a set of RGB images to single band by ...
- 2,599
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votes
2
answers
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Performance of Shapefile and PostGIS with GeoServer?
I'm going to build a web application, which will render around ten maps using GeoServer. I will be also changing the attribute data in the application for some layers.
What is the recommended choice ...
- 1,067
10
votes
5
answers
1k
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How to improve performance when using ArcGIS cursors in Python with big tables?
I have a pretty big point feature class in a file geodatabase (~4 000 000 records). This is a regular grid of points with a 100m resolution.
I need to perform a kind of generalization on this layer. ...
- 1,265
10
votes
1
answer
181
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Explaining long computing time of Python code
I have a Python code adding information to a layer if its features are overlayed by other features. The base layer has 1200 features and is 10 MB. The 4 layers for the overlay have roughly 40 MB ...
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10
votes
4
answers
3k
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ArcGIS 10.2 Query Layer on SQL Server performance
I'm using a Query Layer on SQL Server in ArcMap. The Query Layer executes instantly in in SQL Server but but takes so long to draw in ArcMap that the system appears unresponsive for about 10 minutes ...
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9
votes
8
answers
8k
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Maximizing the use of CPU
My script is intersecting lines with polygons. It's a long process since there are more than 3000 lines and more than 500000 polygons. I executed from PyScripter:
# Import
import arcpy
import time
# ...
- 497
9
votes
2
answers
13k
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Maximizing Code Performance for Shapely
I've written this code in order to calculate the percent cover of grassland within a national park, within 20km^2 of points of recorded occurrences for a species. It is designed to only consider the ...
- 1,274
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votes
3
answers
3k
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Quantitative evidence supporting Solid State Drive (SSD) adoption for ArcGIS Desktop workstations?
Has anyone seen quantitative evidence supporting the use of a SSD (solid state drive) in an ESRI ArcGIS Desktop workstation? Or any GIS workstation for that matter?
I keep reading that SSDs can be a ...
- 932
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votes
1
answer
2k
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Only union/dissolve intersecting or adjacent features to speed up query
I have a table with about 300k polygons, some are overlapping or adjacent to each other and some are islands of their own. I need to dissolve the overlapping/adjacent ones and also keep the non-...
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1
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Any performance difference between Python window and Python script tool?
Is there a difference in performance between running a Python script in the Python window versus running it as a Python script tool from the toolbox in ArcGIS Desktop 10.0?
Sometimes I need to use ...
- 876