Re: should we have a fast-path planning for OLTP starjoins?
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Tomas Vondra <tomas@vondra.me>
Cc: Tom Lane <tgl@sss.pgh.pa.us>,
PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2025-11-24T20:55:25Z
Lists: pgsql-hackers
On Sun, Nov 23, 2025 at 9:39 AM Tomas Vondra <tomas@vondra.me> wrote: > > 1. I do not think I believe the premise that the dimension tables > > typically won't have restriction clauses. ISTM that a typical > > query might be like > > > > select sum(o.total_price) from > > orders o > > join customers c on c.id = o.c_id > > join products p on p.id = o.p_id > > where c.customer_name = 'Wile E Coyote' > > and p.product_name = 'Rocket Skates'; > > > > Good question. I don't have a great evidence such joins to dimensions > (without additional restrictions) are a common case. It's partially a > guess and partially based on my past experience. In my experience, restriction clauses on dimension tables are very common. -- Robert Haas EDB: http://www.enterprisedb.com