Re: hashjoins vs. Bloom filters (yet again)

From: Tomas Vondra <tomas(at)vondra(dot)me>
To: Denis Rodionov <denis(dot)rodionov(at)tantorlabs(dot)com>, Matheus Alcantara <matheusssilv97(at)gmail(dot)com>
Cc: PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>, Andrew Dunstan <andrew(at)dunslane(dot)net>
Subject: Re: hashjoins vs. Bloom filters (yet again)
Date: 2026-09-29 17:20:56
Message-ID: 447b3111-08cf-4a0c-9da5-2eeb28331701@vondra.me
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On 8/24/26 10:39, Denis Rodionov wrote:
> ...
>
> Attached is a proof-of-concept patch (on top of v9-0001..v9-0021) that
> implements the semijoin + false-positive model from my review, to make
> the discussion concrete. It's not meant as a finished patch; it's more
> of "here's what the formula looks like as code, and here's what testing
> it turned up".
>

Ah, I see you've already implemented a PoC of the filter estimation. I
didn't notice that before responding to the earlier message. I'll take a
closer look at this in the next couple days. Thanks!

--
Tomas Vondra

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