Let me first say sorry. I know it's a bit unrelated.. but it seems like the right people are here. Is there any kind of open source database that is close to Am

Let me first say sorry. I know it's a bit unrelated.. but it seems like the right people are here. Is there any kind of open source database that is close to Amazon's QLDB? ideally as a postgresql plugin. Also: is there any "distributed database system" that allows to synchronize for example some tables (or even specific fields) of a server-side database with a third-party client (which might be sqlite vs postgresql in the server side), so that only part of the database is synchronized, in a secure way? this "slave" should not be trusted, think about it as a web user.