[JosephRedfern]

Not OP, but I'd be cool to be able to view the results of a query on a map. For instance, if we did `SELECT * FROM points WHERE created < '2016-07-30'` and Postage detected a spatial column, show the returned geometries on a map (using leaflet.js or something similar, perhaps?).

[justintocci]

Hmm. I don't know. I think we'd need to show them in relationship to some map, like google or bing for it to make any sense though right? Would there be a legal way to do that? Or am I wrong?

Help me out here.

[SOLAR_FIELDS]

I work in this sector - best and simplest use-case is to run your own OSM basemap and satellite tiles and fetch them on the client using Leaflet, embedding them in your application and rendering the data on top of it.

You'd only probably want to support one or two projections out of the box (EPSG 4326 and 3857, the respective geographic and projected coordinate systems that pretty much are the de-facto standard in GIS). The end-user would have to use PostGIS spatial query to project the data if they wanted to see it on map.

Then you would retrieve the extent (bounding box) of the data from the query, send that to your server, fetch the tiles, and have the Leaflet client render basemap under the data. You could look into https://github.com/lukasmartinelli/osm-liberty for some inspiration of self-hosted OSM.

[maxerickson]

For street level detail you could look at using OpenStreetMap. The main requirement there is attribution. But it's a massive amount of data and while there are free services, they do have load limits.

For a less detailed backdrop you could look at Natural Earth. For example, it has inner divisions of countries (so states and the like) in about 15 megabytes:

http://www.naturalearthdata.com/downloads/10m-cultural-vecto...

Or major city/town names in 1.5 megabytes:

http://www.naturalearthdata.com/downloads/10m-cultural-vecto...

(there are also less detailed versions of those datasets intended for use at smaller scales.)

[rmc]

OpenStreetMap could be a good source of a base map with a very liberal licencing issue, You'd only need to have a "Map Data (c) OSM contributors" on the map (IIRC).

The main openstreetmap.org tile servers are liable to block your application if you put too much load on it, but there are plenty of companies which will sell you tile server access, (GeoFabrik, ThunderForest, Mapbox, Mapzen).

[JosephRedfern]

Yeah, context would be useful. Perhaps default to some OSM layers (as others have said, the licensing is liberal), but allow the specification of custom tile-servers in the config for Postage (taking the form of a URL with placeholders for lat, lon and zoom).