logoalt Hacker News

pg_clickhouse v0.10: Subquery pushdown and 1000x faster TPC-H queries

59 points • by saisrirampur • yesterday at 9:54 PM • 5 comments • view on HN

Comments

nasretdinov • today at 7:27 AM

As someone who tried doing things like condition pushdown, transpiling from one language to another, etc, this is really impressive. Correctly pushing subqueries while preserving the semantics of the original database is something I can't imagine I could've ever achieved

manjose2018 • today at 12:24 AM

Please consider comparing pg_clickhouse to pgrust.

https://malisper.me/how-we-made-postgres-hundreds-of-times-f...

➕ show 1 reply
rluisr • yesterday at 11:01 PM

[flagged]

manbash • today at 12:11 AM

> December's headline feature was teaching the planner to push a whole correlated EXISTS subquery down as a single LEFT SEMI JOIN instead of a nested loop with one ClickHouse round trip per outer row. This moved the needle from 3 of 22 TPC-H queries all the way to 12.

LLMs sure love throwing in archaic expressions such as "move the needle". The abrupt contrast in jargons is so unpleasant and keeps throwing me off right in the middle of reading.

➕ show 1 reply