If you have global data, and regional data for two different continents, and they're at different
scales, so you can't easily overlay them without issues, then I'd recommend using different
databases, which would make them completely autonomous. The regional folks would still
have access to the global data for scale-dependent mapping, but their focus would be in
their region. Then you could create owners like transportation, basemap, power, water, etc
in all three databases to standardize the themes of data available, and then get clever in
the naming (to include scale and topology class, if you have room in 31 chars).
I don't have a problem with a huge pile of tables, but when I can, I like to make the
organization as clean as possible.
- V