PostGIS - store 2D elevation data

Question

I am new to PostGIS. How can I store 2D elevation data? I have uniform raster and for every [x,y], height is set. I want to be able to use this in my queries (something like SELECT height FROM data WHERE index = [10, 15]). I also need to write this data from my C++ application (it is not earth elevation data, it is some "planet" surface, that will be modified) and data retrieval must be realtime to be used on website.

So far I have come up with 2 ideas:

Use geometry and store 3D data 2)
Create "2D table" with N columns and N rows (not PostGIS, but classic Postgre solution)

Any better ideas or ways how this should be solved?

My data are approx. 3000x1500

score 1 · Answer 1 · edited Apr 13 '17 at 12:34

1

How big is your dataset?
You could create a fishnet grid in postgis See here
Then you could interpolate your raster with your grid with various tools (gdal/qgis): see here

Dont forget to index your grid to optimize speed. Good luck

edited Apr 13 '17 at 12:34

Community

1

answered Jul 27 '15 at 12:08

julsbreakdown

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The resolution of my dataset is approx. 3000x1500 – Martin Perry Jul 27 '15 at 12:12
Then creating a vector grid is the best bet, I've done this in the past. – julsbreakdown Jul 27 '15 at 12:14
By vector grid you mean fishnet? – Martin Perry Jul 27 '15 at 12:15
Yes, sorry. If it is a oneshot, i would recommend using Qgis. Both tools (fishnet, and pointsamplingtool) are available and easy to use – julsbreakdown Jul 27 '15 at 12:19
It is not oneshot. Data will be updated from C++ application several times a day. – Martin Perry Jul 27 '15 at 12:21
I see. then you should create the fishnet/vector grid just once. And then extract the raster values to you cells (http://gis-lab.info/qa/extract-values-rasters-eng.html) maybe this can help. – julsbreakdown Jul 27 '15 at 12:31

score 0 · Accepted Answer · answered Aug 01 '15 at 14:45

At the end I have used Raster, that is supported by PostGIS directly (but with GDAL extension installed).

It has functions, that suits my needs - see http://postgis.net/docs/manual-2.1/RT_reference.html

I can select value at a certain position directly, also update this value very easy. All operations seems fast enough in read mode (in times of ms).

PostGIS - store 2D elevation data

2 Answers2