Publish all tables for IMPOSM downloads

[migurski]

Right now, it appears as though empty IMPOSM output is not included in the zip file. For example, the Victoria extract is missing barrierways and barrierpoints downloads, even though they are defined in https://github.com/mapzen/chef-mapzen_odes/blob/master/files/default/mapping.json

If that's the correct mapping that the live extracts are using, can we get all shapefiles included even if they are empty? This will help the documentation be a bit clearer.

[heffergm]

I don't believe this is possible. The tables in question likely never make it into postgres because they don't exist in the extract, which means we can't dump them.

[heffergm]

Above is partially incorrect. It looks like we define an array of tables to drop that's partial. I'll update. I'm not sure what we'll end up with if the tables are empty, but if pgsql2shp will still drop some output, they'll be pushed.

[heffergm]

Once this 836b4ea gets pushed out (~30 minutes), you can verify with a new custom extract and if it looks good go ahead and close.

[migurski]

I still see some inconsistencies. For example, this recent extract has 69 files in the IMPOSM SHP download while this one has only 60.

[heffergm]

Take a look at the attributes table of the pbf extract and see if the missing attributes are present. My supposition would be that they're not, as regardless of the mapping imposm won't create tables for things that don't exist in the pbf, which is the source from which imposm is loading data into postgres.