(This is more suitable for the pgsql-general list, you may get more/better replies there)
There is nothing equivalent to ZDLRA in the Postgres world, but there are certainly ways to reduce RTO. You are using replicas, and a tool that saves WALs, so that really gets you 99% of the way there. Tools like pgBackrest can do incremental backups, and parallel, delta-only restores, which can wildly reduce both backup and restore times. RTO for Postgres can be measured in seconds (e.g. Patroni handling a disk failure) to minutes (e.g. someone dropped a table). Also see the recovery_min_apply_delay parameter. If you give us a more specific use case / disaster scenario, we can give more options and advice.
Cheers,
Greg
