tl;dr: There's a new "BI Connector" which will allow you to connect your business intelligence tools to MongoDB using the Postgres wire protocol (which many speak). This is somehow bad because Postgres is also popular, and maybe people will use Postgres now. Also: the author (who has a competing connector) knows the names of a lot of people at MongoDB.
My reading of the article was not that it uses the protocol, but that it actually unpacks it into an actual Postgres database. This obviously looks bad for MongoDB if their analytics literally uses a competing database.
If you're interested in how much computation gets pushed down into the MongoDB database, versus how much gets pulled back into PostgreSQL, you can find some examples here:
Thank you. The writer had way too much fun writing that --at the expense of the actual article. There is about one page of actual information woven into 12 pages of anecdotes of wandering around a conference being exasperated.
