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l3x | 1 year ago

From the FAQs on GitHub [1]

> What about PMTiles?

> I would have loved to use PMTiles; they are a brilliant idea!

> Unfortunately, making range requests in 80 GB files just doesn't work in production. It is fine for files smaller than 500 MB, but it has terrible latency and caching issues for full planet datasets.

> If PMTiles implements splitting to <10 MB files, it can be a valid alternative to running servers.

[1] https://github.com/hyperknot/openfreemap

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apitman|1 year ago

That's an interesting claim. I make range requests to 100GB+ files (genomics) all the time for work and it works great. I've never considered total file size as directly related to latency in this respect, assuming you have some sort of an index of course.

hyperknot|1 year ago

Here the requests are really really small, on average 405 bytes each. I guess in your genomics work you are making larger requests, so probably it's not so much of an issue.

BTW, we are discussing latency with bdon in this issue, it seems to be specific to Cloudflare: https://github.com/hyperknot/openfreemap/issues/16

tobilg|1 year ago

If you store the PMTiles in S3 or any other object store that supports HTTP Range Requests, that's a no-brainer... In a normal disk on you own server, this might become interesting, yes.

mistrial9|1 year ago

ok except "full planet datasets" make little sense for terrestrial features. Splitting .. aka sharding the files into basic continents would make SO much sense. Asia is big, but no requests for Africa mixed in.. Australia would be manageable?

hyperknot|1 year ago

PMTiles could come up with a version in the future where instead of one 90 GB file, they have 9 thousand 10 MB files. That would work well I believe.