Appreciate you chiming in! We evaluated almost all the FDWs and landed on clickhouse_fdw (built by Ildus) as the most mature option. However, it hadn’t been maintained since 2020. We used it as the base, and the goal is to take it to the next level.

Our main focus is comprehensive pushdown capabilities. It was very surprising to see how much the Postgres FDW framework has evolved over the years and the number and types of hooks it now provides for push down. This is why we decided to lean into FDW than build an extension bottoms up. But we may still do that within pg_clickhouse for a few features, wherever FDW framework becomes a restriction.

We’ve made notable progress over the last few months, including support for pushdown of custom aggregations and SEMI JOINs/basic subqueries. Fourteen of twenty-two TPCH queries are now fully pushdownable.

We’ll be doubling down to add pushdown support for much more complex queries, CTEs, window functions, and more. More on the future here - https://github.com/ClickHouse/pg_clickhouse?tab=readme-ov-fi... All with the goal of enabling users to build fast analytics from the Postgres layer itself but still using the power of ClickHouse!

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DetroitThrow 3 days ago | parent [-]

>All with the goal of enabling users to build fast analytics from the Postgres layer itself but still using the power of ClickHouse!

That would be incredible! So many times I want to reach for ClickHouse but whatever company I'm at has so much inertia built into PG. Pleease add CTE support.

And yes I'm aware of PeerDB or whatever that project is called. This is still or even more helpful.

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saisrirampur 3 days ago | parent | next [-]

Totally! Making things way easier on the app and query side is very important, which is why we plan to invest heavily in this going forward.

With respect to data replication, it gets really hard and has its challenges as data sizes grow - reliably moving tens of terabytes at speed, handling intricate quirks around replication slots, enterprise-grade observability etc. PeerDB/ClickPipes is designed to solve these problems. I wrote a blog post covering this in more detail here: https://clickhouse.com/blog/postgres-cdc-year-in-review-2025

That said, point taken - we will ensure query and app migration is seamless as well and reduce friction in integrating Postgres and ClickHouse. pg_clickhouse is a step in that direction! :)

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__s 3 days ago | parent | prev [-]

You're replying to the CEO of PeerDB. We recognize CDC is only one tool in the integration toolbox, which is why we're prioritizing this

	▲	DetroitThrow 7 hours ago \| parent [-]
		I shouldn't be so flippant on here, of course I'm talking to the guy who wakes up and hears this every day. I really appreciate the work that he and y'all are doing on both sides of the equation, it's great for every org that wants to use ClickHouse but can't.