alt Hacker Newspg_mooncake (now effectively abandoned due to being acquired by Databricks, but still up at https://github.com/Mooncake-Labs/pg_mooncake) pulled the DuckDB engine into Postgres wholesale, if I remember right.
pg_lake also uses DuckDB but keeps it external, routing through Postgres and managing Iceberg tables (but not the data itself) there (https://github.com/Snowflake-Labs/pg_lake).
Both of these were neck and neck with ClickHouse last time I tried them.
Actually δx is faster than the "duckdb embedded in postgres" options: https://benchmark.clickhouse.com/#system=+_etx|_b|_i)|dula|pnc&type=-&machine=-6t|ca2|6ax|g4e|6ale|3al&cluster_size=-&opensource=-&hardware=+c&tuned=+n&metric=combined&queries=-
Plus all the normal Postgres features work as expected: physical/logical replication, crash recovery, pg_dump/pg_restore, etc.