[OSM-dev] Timestamp in PBF files

[marqqs at gmx.eu]

Hi Brett,

> *If* this information is intended to be used as an input into replication
> processes then the sequence number is essential.  Osmosis writes a
> timestamp in the state.txt file, but it only for identifying the right
> sequence number to begin replication with.  All replication processing
> requires the sequence number.  Attempting to use a timestamp is
> theoretically possible but it's much less efficient and not how it was
> supposed to work.

I think this is true for database based updates, however the sequence number is not really needed for file based updates we're presently talking about:

For example, osmupdate downloads all change files, starting with the newest, going back in time until the the change file has been downloaded which is newer than the planet files timestamp. Then all these change files are merged to one big change file which is then applied to the planet file.

Osmosis may work differently, and it may need the sequence number to start this kind of file update - I really don't know. But if so, I totally agree, we should make it possible to store sequence numbers in PBF files.

Could also be done with the key-val format I suggested...

Markus