Re: Deleting older versions in unique indexes to avoid page splits - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Deleting older versions in unique indexes to avoid page splits
Date
Msg-id 20210120052021.l5ygiuw66nk2htet@alap3.anarazel.de
Whole thread Raw
In response to Re: Deleting older versions in unique indexes to avoid page splits  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: Deleting older versions in unique indexes to avoid page splits  (Amit Kapila <amit.kapila16@gmail.com>)
List pgsql-hackers
Hi,

On 2021-01-20 09:24:35 +0530, Amit Kapila wrote:
> I feel extending the deletion mechanism based on the number of LP_DEAD
> items sounds more favorable than giving preference to duplicate
> items. Sure, it will give equally good or better results if there are
> no long-standing open transactions.

There's a lot of workloads that never set LP_DEAD because all scans are
bitmap index scans. And there's no obvious way to address that. So I
don't think it's wise to purely rely on LP_DEAD.

Greetings,

Andres Freund



pgsql-hackers by date:

Previous
From: Michael Paquier
Date:
Subject: Re: Some coverage for DROP OWNED BY with pg_default_acl
Next
From: Peter Geoghegan
Date:
Subject: Re: Deleting older versions in unique indexes to avoid page splits