Real-time Change Data Capture from Postgres 16 Read Replicas

PeerDB introduces Change Data Capture (CDC) from Postgres 16 Read Replicas, offering a fast and simple experience for replicating data from Postgres to various destinations. This feature eliminates risks on the Primary Postgres Database by enabling CDC/replication from Read Replicas instead of Primaries. PeerDB's learnings while building this feature include: 1. CREATE_REPLICATION_SLOT works as expected on Read Replicas. 2. SNAPSHOT can be created and used on Read Replicas. 3. START_REPLICATION worked as expected on Read Replicas. 4. Publications cannot be created on the Read Replica, requiring manual creation on the primary. 5. WAL control functions cannot run on Read Replicas, necessitating a conditional query using pg_last_wal_receive_lsn() for replicas. To try out this new feature, users can fill out the Request for Access form on PeerDB's website or visit their GitHub repository to Get Started.