Not the same percentage of them. Postgres has been used for a shorter time in large companies. Many experts in Postgres were previously experts in another DBMS.

Not the same percentage of them. Postgres has been used for a shorter time in large companies. Many experts in Postgres were previously experts in another DBMS. In contrast, most Oracle DBAs/Engineers publish the fact that they have only used this specific product during their whole career. They seem to be rather proud of the fact, actually.