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No, and no.
RepMgr uses PostgreSQL’s WAL-based replication. That will only work with the same version of PostgreSQL and for a whole cluster. You’ll probably want to have at least a vague familiarity with the PostgreSQL manual before implementing a replicated cluster.
If you want partial replication (one database or even a few tables from a database) or different versions check out trigger-based replication such as slony or bucardo.
Source:stackexchange.com