Closed bdon closed 2 years ago
add tile type as a required metadata field (png, jpg, mvt, etc)
Flaws in current design:
New design:
clustered:true
indicates that the tile order on disk matches TileId orderUnsolved problems:
target metric: (total # of tiles in archive / size of index in bytes) = average number of bytes per tile entry Currently this is 17, 3-5 bytes per entry is what my experimental results are...can we do better?
Parquet encodings: https://parquet.apache.org/docs/file-format/data-pages/encodings/
bbox
, minzoom
, maxzoom
, tile_type
, compression
, clustered
Consider if we should add leaders/trailers: https://gdal.org/drivers/raster/cog.html
the COG 16KB assumptions seem good
Ghost sections / extensions, example: storing offset->hash in a ghost section to enable efficient diffing of two PMTiles archives
Options:
Use cases: