public inbox for [email protected]  
help / color / mirror / Atom feed
From: Heikki Linnakangas <[email protected]>
To: cca5507 <[email protected]>
To: pgsql-hackers <[email protected]>
Subject: Re: Support loser tree for k-way merge
Date: Wed, 3 Dec 2025 14:23:53 +0200
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>

On 03/12/2025 13:48, cca5507 wrote:
> With the WIP patch(v1-0001), I got a 3% ~ 13%(different work_mem) speed up in the following test case:

Nice speedup!

> 1) Now I add a GUC 'enable_loser_tree' to control the use of loser tree, maybe we should
> decide whether to use the 'loser tree' based on the value of 'k', the complexity of tuple
> comparators or just always use the 'loser tree'?

What is the worst case scenario for the loser tree, where the heap is 
faster? How big is the difference?

- Heikki






reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected]
  Subject: Re: Support loser tree for k-way merge
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox