DSQL only uses Postgres for the query processor layer, so it doesn't require a replication library within postgres itself. Definitely NOT from DSQL.

> We’re not using any of the storage or transaction processing parts of PostgreSQL, but are using the SQL engine, an adapted version of the planner and optimizer, and the client protocol implementation. [1]

Rather, DSQL seems to do its region replication using the distributed journal abstraction [2].

[1] https://brooker.co.za/blog/2024/12/04/inside-dsql.html [2] https://brooker.co.za/blog/2024/12/06/inside-dsql-cap.html