Sai from PeerDB/ClickHouse here. Nice to see the progress on this project! I wanted to leave a few notes:<p>For analytics on transactional data, it looks like you'd still need to use logical replication (<a href="https://github.com/Mooncake-Labs/pg_mooncake/issues/90">https://github.com/Mooncake-Labs/pg_mooncake/issues/90</a>). Logical replication is somewhat similar to an ETL/CDC experience, though it's more Postgres-native. Managing logical replication at a production grade isn't trivial — it's quite common for customers to use PeerDB for homogeneous replication due to performance, manageability and observability issues with logical replication.<p>One potential value of extensions is Postgres compatibility for your queries. However, I'm curious about the SQL coverage on columnar tables — for example, advanced constructs like partitioned tables, prepared statements, correlated subqueries, RCTEs, triggers, and more. While it seems there’s ongoing work to improve compatibility, achieving full Postgres compatibility is challenging. In some cases, you might need to fall back to Postgres (instead of DuckDB), sacrificing performance for certain queries.<p>The biggest challenge we faced at Citus was the constant trade-off between Postgres compatibility and performance — both are complex and constantly moving targets. This was the key reason why Citus couldn't compete with purpose-built databases like Snowflake, ClickHouse, SingleStore. While DuckDB didn’t exist when we built Citus, it's still fundamentally different from Postgres. Even though the DuckDB dialect is somewhat similar to Postgres (as is Snowflake’s), retrofitting two distinct databases — each evolving independently for world's best performance — isn't trivial.<p>In short, relying on ETL (logical replication) without providing full Postgres compatibility raises the question: is it better to lean on a purpose-built database with a laser focus on performance, or adopt a more generalized approach?<p>Anyway, I come from a different school of thought — using the right tool for the right job. That said, I love seeing all the progress and evolution in the Postgres community — Postgres will always be my first love!