I need to run PostgreSQL in-memory (for performance reasons), so I intend to disable fsync, which means that no writes will be sent to the WAL.
However, as part of my scheme to meet another requirement (that the in-memory database have somewhere to recover from when volatile memory is lost), I would like to stream or otherwise push writes to a replica. However, the PostgreSQL hot standby capability is based on the WAL. Clearly, I can't use this.
How could I achieve these goals using PostgreSQL features?