To add to Adrian's questions here are my 5 cents
Postgres is a community that consists of people from different companies with variety of interests:
- Postgres/open source/community-focused interests
- personal interests
- their company's interests
To create a fully "unbiased" certification there is a need for a working group whose interests would be fully aligned.
I must admit, I'm a bit pessimistic about a unified Postgres certification as it would put people who would be working on it in a difficult situation when they're serving all the abovementioned interests.
Valeria