Optimisation is the act of making things as good as possible with regard to some criterion, eg. more efficient, faster or slimmer.

learn more… | top users | synonyms

8
votes
4answers
1k views

Fastest spatial storage format?

I am wondering what storage method will result in the fastest reading of the map vectors for rendering. SHP? PostGres? SQLite? (They do not change often and I do not need spatial functions for these ...
35
votes
3answers
6k views

Are there newer routing algorithms (than Dijkstra, A*) in GIS databases?

There are works like Reach for A* from Microsoft researchers and Highway Hierarchies by Sanders and Schtolz (if I spell the name correctly) from Karlsruhe Uni. Both of them reduce the calculations ...
4
votes
2answers
905 views

Qgis is slow with complex 'postgis query' layer. How to speed up?

I have a postgis layer in Qgis that is a result of a complex query. Every screen update, Qgis runs the Query again and that's slow. Any suggestion on how to speed up? EDIT - Here is the query: ...
6
votes
4answers
3k views

ST_Intersection slow query

I am trying to perform an intersection between two layers: Polyline layer representing some roads (~5500 rows) Polygon layer representing irregularly shaped buffers around various points of interest ...
8
votes
4answers
1k views

Performance of google map tile creation processes

I know that question is rather vague but please bear w/me. I'm trying to get an idea of what sort of product performance - specifically timing - people have seen for various methodologies they have ...
11
votes
5answers
2k views

Speeding up OpenStreetMap PostGIS querying

I have OpenStreetMap data for the Netherlands loaded into a PostGIS database (PostgreSQL 8.3 / PostGIS 1.3.3) using the osmosis schema. This means all tags are stored in a hstore field. In addition to ...
22
votes
5answers
8k views

Optimizing osm2pgsql imports for OSM data

I'm currently building an instance on EC2 on which to import the entire Planet.osm snapshot of the whole Earth's worth of data for some projects we're working on. I've spun up a large Ubuntu x64 ...
7
votes
3answers
3k views

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 ...
3
votes
2answers
1k views

Postgres/PostGIS Spatial Query Performance Problem

I have a query in Postgres/PostGIS that I am a bit confused about. The spatial intersection happens very fast, ~ 2 seconds for 10,000, but the update takes > 15 seconds for the same number of points. ...
8
votes
4answers
1k views

Best way to find the polygons crossed by a line

I'm trying to find all the polygons crossed by a single line (a GPS track). I'm using the OGR library (from python) for computing this, but it's currently a bit 'brute-force' (and slow). For every ...
6
votes
5answers
1k views

Effectively displaying a large amount of data on Google Maps APi

I have about 20 layers that I'd like to put on a Google maps API. I assume I'll need some form of a tile cache server and perhaps under mapserver or geoserver. These layers amount to about 400mb so ...
6
votes
1answer
567 views

Is there anyway to make GPModels with python scripts execute faster?

I do not know if anyone else has this problem but my GPModels that include simple python scripts seem to take way too long to execute. One example is a model I built which is a simple select feature ...