osm2pgsql - how to store relation parts


I am developing an application that needs OSM relations and their constituent OSM IDs.

Is there a way to get osm2pgsql to store OSM relation ID and the parts that form the relation?

I know that if I use --slim then the parts are stored in planet_osm_rels.parts, but I would like to avoid using --slim because (1) it’s considerably slower and (2) it uses a lot of disk space.

From what I can see, there’s no way to do it using a style file alone, but I may be able to do it using the ‘multi’ interface (I haven’t got any experience with this yet though).

I am not wed to osm2pgsql. So alternatively, if there’s no clean way to do it with osm2pgsql, could osmium or osmosis be used to achieve this?