ClickHouse open-sources WalShadow, replicating Postgres into ClickHouse from physical WAL

Sources: primary, HN item
Summary: ClickHouse released WalShadow as open source. It replicates Postgres into ClickHouse from the physical write-ahead log rather than through a logical replication slot, and the managed path is a private preview limited to ClickHouse Managed Postgres. ClickHouse benchmarked its own tool against its own earlier PeerDB on c8i.2xlarge instances with 8 vCPUs and reports roughly 200 ms commit-to-visible latency against roughly 50 ms for a native Postgres physical standby and roughly 10 seconds for PeerDB, and 289,000 rows per second sustained against roughly 290,000 at the source and roughly 120,000 for PeerDB.
Why it matters: It removes logical replication slots and their decoding cost from the source database, at the price of needing physical WAL access that most managed Postgres providers do not expose.