Comments on: No more snapshot too old in PostgreSQL 17 https://www.dbi-services.com/blog/no-more-snapshot-too-old-in-postgresql-17/ Mon, 27 May 2024 15:38:47 +0000 hourly 1 By: Franck Pachot https://www.dbi-services.com/blog/no-more-snapshot-too-old-in-postgresql-17/#comment-3286 Mon, 27 May 2024 15:38:47 +0000 https://www.dbi-services.com/blog/?p=27681#comment-3286 Hi Daniel. I guess the workaround is transaction timeout, I see it has been accepted: https://commitfest.postgresql.org/45/4040/

]]> By: Daniel Westermann https://www.dbi-services.com/blog/no-more-snapshot-too-old-in-postgresql-17/#comment-2876 Tue, 26 Sep 2023 16:35:37 +0000 https://www.dbi-services.com/blog/?p=27681#comment-2876 In reply to Di.

Everybody is welcome to provide or propose patches. It is not me/us deciding about this, it is the commumity

]]> By: Di https://www.dbi-services.com/blog/no-more-snapshot-too-old-in-postgresql-17/#comment-2875 Tue, 26 Sep 2023 15:53:29 +0000 https://www.dbi-services.com/blog/?p=27681#comment-2875 This feature is extremely important for us and removing it will prevent us from upgrading to Postgres 17 when it comes out without a solid solution for the problem it solves for us.

]]> By: Daniel Westermann https://www.dbi-services.com/blog/no-more-snapshot-too-old-in-postgresql-17/#comment-2874 Tue, 26 Sep 2023 07:16:43 +0000 https://www.dbi-services.com/blog/?p=27681#comment-2874 In reply to Di.

Hi, currently there is no solution but maybe someone comes up with one.

]]> By: Di https://www.dbi-services.com/blog/no-more-snapshot-too-old-in-postgresql-17/#comment-2873 Tue, 26 Sep 2023 02:26:28 +0000 https://www.dbi-services.com/blog/?p=27681#comment-2873 See these threads that discuss the problem:
https://dba.stackexchange.com/questions/239777/how-do-we-get-around-postgresql-autovacuum-taking-a-table-level-lock-access-excl
https://dba.stackexchange.com/questions/323724/postgresql-12-streaming-replication-standbys-timing-out-due-to-autovacuum-tasks

]]> By: Di https://www.dbi-services.com/blog/no-more-snapshot-too-old-in-postgresql-17/#comment-2872 Tue, 26 Sep 2023 02:24:18 +0000 https://www.dbi-services.com/blog/?p=27681#comment-2872 In our system, we’ve had to set old_snapshot_threshold in order to deal with waits on very large and active tables (multi-terrabyte) in our streaming replicas that caused connections to time out and cancel. We ended up setting the value to our longest query + some additional factor (which in our case was the backup which also runs from a standby). Previous to this we tried other solutions and none worked. We do not want to have to specifically set vacuum_truncate=off either, as these same tables previously had a lot of table bloat to contend with, and this allowed atleast a watermark so that those older transactions could be truncated and space returned back to the OS. So how will this be solved in version 17?

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