pg_clickhouse v0.10 Subquery Pushdown: 1000x Faster TPC-H Queries in 2026
pg_clickhouse v0.10, released August 11, 2026, finally pushes correlated subqueries (SubPlans) down into ClickHouse, moving the TPC-H scoreboard from 12 to 16 of 22 queries fully pushed down. The headline result is TPC-H Q17, which dropped from 32.7 seconds to 37 milliseconds — roughly 880x faster and beating native PostgreSQL’s 2.1 seconds. This guide explains how subquery pushdown works, how to verify it with EXPLAIN, and what you need to upgrade to take advantage of it. ...