I'm glad you cleared that up, because for a moment there I thought your comment was advocating for Postgres in a thread ostensibly about MySQL by pointing out that pg_dump has baked-in compression; an optimization which could potentially shave milliseconds off a process that the article mentioned can take over 12 hours on large tables.

So, putting aside the issue of Postgres not supporting mysqldump for the moment, there is also the issue of Postgres having poor support for the InnoDB on-disk format, and practically non-existent support for the MySQL client protocol. The more I think about this, the more I realize just how unsuitable Postgres is for Pinterest's current environment.