# Postgres FDW: Pushdown is a negotiation

DevFeed: [Postgres FDW: Pushdown is a negotiation](<https://devfeed.tech/articles/postgres-fdw-pushdown-is-a-negotiation-5513.md>)

Original publisher: [Read original article](<https://clickhouse.com/blog/postgres-fdw-pushdown-negotiation>)

Author: Kaushik Iska; David Wheeler; Philip Dubé

Published: 2026-05-14T00:00:00Z

Content type: article

Language: en

Sources: [ClickHouse Blog](<https://devfeed.tech/sources/clickhouse-blog.md>)

Topics: [clickhouse](<https://devfeed.tech/topics/clickhouse.md>), [SQL](<https://devfeed.tech/topics/sql.md>), [Databases](<https://devfeed.tech/topics/databases.md>), [systems](<https://devfeed.tech/topics/systems.md>), [Code](<https://devfeed.tech/topics/code.md>)

Tags: [analytics](<https://devfeed.tech/tags/analytics.md>), [clickhouse](<https://devfeed.tech/tags/clickhouse.md>), [code](<https://devfeed.tech/tags/code.md>), [deep-dive](<https://devfeed.tech/tags/deep-dive.md>), [engineering](<https://devfeed.tech/tags/engineering.md>), [postgres](<https://devfeed.tech/tags/postgres.md>), [sql](<https://devfeed.tech/tags/sql.md>)

## AI overview

A deep dive into how the pg_clickhouse Foreign Data Wrapper negotiates SQL pushdown between Postgres and ClickHouse. It examines which query clauses can be sent to the remote system, which require rewriting or local execution, and how iterative engineering affects performance and correctness.

## Source excerpt

A deep dive into how pg_clickhouse's Foreign Data Wrapper decides what SQL to push down to ClickHouse versus execute locally in Postgres .