On 27/11/15 08:13, Gerd Petermann wrote:
- Whatever DB design is used now is considered to be unable to store more attributes without changing the DB design.
No that's not true, More attributes can be added, but only when a full reload is done.
I mean we could add the extra columns to the existing database, but they would only get populated for changes made after that date and wouldn't be backfilled with values for existing objects.
In theory somebody could write something to read the planet and backfill those columns but I don't believe it exists currently.
- it was decided that the new design has to use hstore
No, it was decided that it probably makes sense to use hstore for the less common attributes because it means you're not creating lots of columns that are mostly empty.
Whether hstore or new columns are used doesn't really matter - in either case adding the column without a reload would mean the data was missing for existing objects.
- nobody has made progress understanding how hstore works since then.
I have no idea why you think this. We understand perfectly well how it works and plenty of people have stylesheets using it.
Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ _______________________________________________ dev mailing list dev@openstreetmap.org https://lists.openstreetmap.org/listinfo/dev
