[Answered ]-Separating GEO database from normal database

If you are concerned about performance, it is obvious that the data needs to be in one database.

Spatial isn’t special, it’s just another data type. I don’t see why enabling PostGIS would compromise the performance of a database. However, it doesn’t hurt to test this with a copy of the primary database, particularly for production environments.

If you are concerned that enabling PostGIS will add hundreds of functions to the “public” schema, you can make a “postgis” schema and put the extension there. See these details. However, I’m not sure how geodjango will cope with this setup.