public inbox for [email protected]
help / color / mirror / Atom feedFrom: Scott Ray <[email protected]>
To: Kyotaro Horiguchi <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Subject: Re: Report oldest xmin source when autovacuum cannot remove tuples
Date: Wed, 03 Jun 2026 01:05:13 +0000
Message-ID: <qOUvBIi7LC3GLKEjACMQAhPnYaE1m7Ta6XbMXN1gOVo3Mh6-Be6o_kQxQeCNXfo-Ywgc8k6myZrco4a41z-r7Dfqro4-nH73cB_tmSOczJk=@scottray.io> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
<3bnBUxwx2npXqvHL0trI11LOOvzQ7LI0GzWqbaj5SJnk7DTb1uzStGveKwj0JJmBW4ebzGIF3az7of4I4rQeaO_PRqDnnClCduPyjM6gPgM=@scottray.io>
<CAOzEurTC+5xuH_X2EBWjW0Fs9iuTq3OMA=1FfT4xx1wYbCAR6g@mail.gmail.com>
<[email protected]>
> What I would want to investigate after seeing such a signal is not
> necessarily what happened to be blocking that particular VACUUM
> operation at some earlier point, but what is holding the xid horizon
> back now. For that purpose, a view exposing the current xid/xmin
> holders seems more useful and less misleading than adding a
> best-effort blocker guess to the VACUUM log.
I've been working on a view like this. It shows the horizon
contribution for each backend, prepared xact, replication slot, and
HSF walsender, broken down by class. It also shows - for each
contributor - how the horizon would shift if that holder were
removed.
Shinya said [1] that we could have a view in the future. We could
have both the logging and the view call a single function that reads
the procArray and other sources to gather the horizon information. I
think the logging and the view would complement each other.
Should I start another thread?
[1] https://www.postgresql.org/message-id/[email protected]...
--
Scott Ray
Attachments:
[application/pgp-signature] signature.asc (343B, 2-signature.asc)
download
view thread (34+ messages) latest in thread
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], [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: Report oldest xmin source when autovacuum cannot remove tuples
In-Reply-To: <qOUvBIi7LC3GLKEjACMQAhPnYaE1m7Ta6XbMXN1gOVo3Mh6-Be6o_kQxQeCNXfo-Ywgc8k6myZrco4a41z-r7Dfqro4-nH73cB_tmSOczJk=@scottray.io>
* 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