"pmtiles merge" CLI command?

[mgibbs189]

I have a 120GB raster dataset, split into 2600 geotiffs. Extracting a .pmtiles from it hasn't been easy 🙃

Would you consider adding a pmtiles merge CLI command?

See below for the different approaches I've tried, and how a pmtiles merge command could help.

Option 1: gdal_merge of the geotiffs, then gdal_translate to .mbtiles

[-] Single-threaded [-] painfully slow [-] gdal requires ludicrous amount of free space (7+ TB)

Option 2: Convert each geotiff to its own .mbtiles file, then merge the .mbtiles files together

[+] multi-threaded, minus the merging [-] tippecanoe's tile-join doesn't support rasters

Option 3: gdal2tiles -> directory of .pngs, then mb-util to generate merged .mbtiles, then .pmtiles

[+] png creation multi-threaded [-] creating millions of pngs is torture on the filesystem [-] slow

Option 4 (proposed): Convert each geotiff into its own .mbtiles file, then pmtiles convert for each, then pmtiles merge to stitch all the pmtiles together

[+] multi-threaded [+] fast(?)