[gdal-dev] gdal mdim convert and grib2

[Scott]

Using:
GDAL 3.12.0 "Chicoutimi", released 2025/11/03

The following returns almost immediately, if you know the band number. 
Unfortunately, with this data set, the bands and arrays aren't 
consistent across model runs, so I can't rely on a fixed band. A 
grib2.idx does exist on S3 (which is why using band works so fast):

gdal raster select -i 
/vsis3/noaa-nbm-para-pds/blend.20251104/01/core/blend.t01z.core.f059.co.grib2 
-o blend.t01z.core.f059.co.tif --band 132 --co COMPRESS=DEFLATE --overwrite

The following takes over 4 minutes to complete. Downloading the file 
locally only takes about 20 seconds.

time gdal mdim convert -i 
/vsis3/noaa-nbm-para-pds/blend.20251104/01/core/blend.t01z.core.f059.co.grib2 
-o blend.t01z.core.f059.co.tif --array "QPF06_0-SFC" --co 
COMPRESS=DEFLATE --overwrite

If I download the file first, so it's local, then it completes immediately.

Any thoughts on speeding this up? Ideally, I don't want to download the 
file first.

Thanks!
Scott


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