[midom]

> Facebook has gone through many databases.

Main use cases (social graph, messaging, ..) are on MySQL (and never left it). Storage engine is different, replication is improved, etc, but it is still tracking upstream MySQL tree.

The thing is - PG still relies on physical replication, and staying with logical one allows to use it for out-of-DBMS change data capture and reuse in other systems.

> MediaWiki is ...

Funny tidbit - I tried to move over Wikipedia to PG ages ago, and did the initial prototyping and made it work to a certain degree. But also I learned about InnoDB more at the time.