The version of Postgis turns out to be too old to be used by the Maps team, please install Postgis 2.1.7 and Postgress 9.4. Per community input, the OSM database should be dropped and re-imported. Updating to Jessie is not a requirement.
Also, according to the OSM community (Paul), the default Postgres server configuration is very inefficient, and needs to be updated. Please see http://www.paulnorman.ca/blog/2014/11/new-server-postgresql-tuning/
Per @yuvipanda, other users are ok with this.