Another useful angle to look at the PostgreSQL-compatible database landscape would probably be fully open source (e.g. Apache licensed) vs. almost open-source (

Another useful angle to look at the PostgreSQL-compatible database landscape would probably be fully open source (e.g. Apache licensed) vs. almost open-source (e.g. AGPL or commercial licenses that convert to Apache after a few years) vs. closed source. For a variety of reasons, many large organizations that seek to build an internal multi-cloud / hybrid cloud database-as-a-service platform strongly prefer fully open-source solutions.