[GRASS-user] Slow import of GHSL

[Markus Neteler]

On Fri, Mar 10, 2017 at 5:47 PM, Nikos Alexandris
<nik at nikosalexandris.net> wrote:
> Why does (attempting to) import a 38m pixel resolution GHSL [0] GeoTIFF
> layer, ie GHS_BUILT_LDS1990_GLOBE_R2016A_3857_38_v1_0_p1.tif, in GRASS'
> db progress slow?

Can you elaborate a bit more? I have downloaded and checked:

That is 9835059101  bytes in 19885 files or I downloaded the wrong one
(please post an URL).

> Similar GHSL data sets vary between 300 ~ 500 MB in size.

Yes - do you have a SSD disk? This quite helps along with a
sufficiently large GDAL cache ("memory" parameter of r.in.gdal).

> As well, trying to clip the GeoTIFFs (not the VRT files) with gdal
> tools to a custom extent (say Europe), appears to be a heavy process.

With GDAL, be sure to have set something like
export GDAL_CACHEMAX=2000

HTH,
Markus

> Thanks for hints, Nikos
>
> [0] http://ghsl.jrc.ec.europa.eu/