pg_clickhouse v0.10.0 pushes down 16 of 22 TPC-H queries and adds guards for a NULL semantics mismatch that silently inverted NOT IN

Sources: primary, discussion
Summary: ClickHouse reports that pg_clickhouse v0.10.0 pushes 16 of 22 TPC-H queries down to ClickHouse. The release adds guards for a semantics mismatch in IN, where ClickHouse uses two-valued logic and PostgreSQL uses three-valued, so a naive pushdown of NOT IN returned rows PostgreSQL would have filtered out.
Why it matters: The mismatch produced wrong results under a plan that looked correct, which is the failure mode a pushdown extension has to close before its benchmark numbers mean anything.