file size change with apply-changes
Closed this issue · 4 comments
What version of osmium-tool are you using?
osmium version 1.14.0
libosmium version 2.18.0
Supported PBF compression types: none zlib lz4
What operating system version are you using?
macOS 12.3.1 (21E258)
Tell us something about your system
What did you do exactly?
osmium apply-changes planet-latest.osm.pbf ${CHANGES} -o ${PREFIX}-planet.osm.pbf
where changes is a string which lists 14 osc.gz files, totalling 1.1 GB
What did you expect to happen?
moderate increase in file size
What did happen instead?
planet grew from 63GB to 66GB
Maybe this is expected?
osmium fileinfo -e 220513-planet.osm.pbf
File:
Name: 220513-planet.osm.pbf
Format: PBF
Compression: none
Size: 70854841060
Header:
Bounding boxes:
With history: no
Options:
generator=osmium/1.14.0
pbf_dense_nodes=true
[======================================================================] 100%
Data:
Bounding box: (-180,-90,180,90)
Timestamps:
First: 2005-05-03T13:27:18Z
Last: 2022-05-12T23:59:22Z
Objects ordered (by type and id): yes
Multiple versions of same object: no
CRC32: not calculated (use --crc/-c to enable)
Number of changesets: 0
Number of nodes: 7681064403
Number of ways: 858426049
Number of relations: 9901076
Smallest changeset ID: 0
Smallest node ID: 1
Smallest way ID: 37
Smallest relation ID: 11
Largest changeset ID: 0
Largest node ID: 9736075728
Largest way ID: 1059705347
Largest relation ID: 14134073
Number of buffers: 12098575 (avg 706 objects per buffer)
Sum of buffer sizes: 760890019528 (725.641 GB)
Sum of buffer capacities: 793243811840 (756.496 GB, 96% full)
Metadata:
All objects have following metadata attributes: version+timestamp+changeset
Some objects have following metadata attributes: all
The planet you can download on planet.osm.org is generated with a program that doesn't use libosmium. It encodes OSM data slightly different than how libosmium does it. Also we don't know what those changes are, they might well result in some objects moving into a different block inside the PBF or something like that making the whole file larger. So without looking at the details it is well possible that the file you get is somewhat larger than expected. I wouldn't consider this a bug.
the diffs are the daily diffs from OpenStreetMap 2/5-today
after continuing with the updates to the file I have found that the initial increase is now stable (not growing unexpectedly any more) which kind of confirms that the size differences are likely due to a different way of saving the pbf and not a problem.