[Rebuild] Idea for ODbL transition strategy

[Frederik Ramm]

Hi,

On 01/31/12 23:41, errt at gmx.de wrote:
> I'll reexamine my proposed approach in the same style for better
> comparison, but not in that detail for now:

I'm not completely against that approach, as I said before, having a 
"pure" database in the end is a nice thing. But I think that the side 
effect of changing history without any accounting is not acceptable.

The history database says clearly "on date X, user Y uploaded this 
object with properties Z". Simply changing Z ex-post is falsifying 
history. That's just wrong. We can choose to hide Z, but we must not 
change Z to be something else and then claim the user uploaded that.

> This approach would probably quite a lot free database space and
> renumbering objects is possible, but not needed.

I don't have a proper simulation either but let's assume that we lose 5% 
of data in the relicensing process, then that would bring us down from 
2.4 TB to 2.15 TB; in about 4 months we's be back at 2.4 TB 
(http://munin.openstreetmap.org/openstreetmap/smaug.openstreetmap/postgres_size_openstreetmap.html) 
so the saving is probably not that big.

> P.S.: I still think it's a major question whether we want to keep but
> hide non-ODbL versions or whether to drop them completely for the sake
> of a smaller, clean database and no needs for any patches for holes or
> invisible versions. We should probably have a voting on that fundamental
> decision, at the best a community vote.

I don't think this is a good idea.

Bye
Frederik