PostgreSQL Logical replication Practical use case

Replication slot is not active for a standby or replication data lagging values are null Meaning: The standby replication slot active flag value is false or

active active_pid xmin catalog_xmin

replication slot is active for pid And this finally explains why that inactive replication slot causes the retention of that much WAL on an idle database: there actually are some

replication slot already exists Logical replication worker for each subscription Logical replication launcher Connect Add