a8c9d2be28
'ALTER SUBSCRIPTION ... REFRESH SEQUENCES' can race with a running sequence synchronization worker. If the worker has fetched a sequence's value from the publisher but not yet marked it READY, a concurrent refresh that resets the sequence to INIT can be overwritten by the worker's stale value, silently losing the refresh request. Handle this by stopping any running sequence sync worker before resetting the sequences to INIT. This is race-free because AlterSubscription() already holds AccessExclusiveLock on the subscription object. That lock blocks a running worker's UpdateSubscriptionRelState(), which takes AccessShareLock on the object, and also any worker the apply worker re-launches, because a new worker takes AccessShareLock on the object in InitializeLogRepWorker() before it reads pg_subscription_rel. Such a worker cannot act on the sequence states until the refresh commits, by which time they are reset to INIT and it will synchronize the latest publisher values. Reported-by: Noah Misch <noah@leadboat.com> Author: Amit Kapila <amit.kapila16@gmail.com> Reviewed-by: vignesh C <vignesh21@gmail.com> Reviewed-by: Shveta Malik <shveta.malik@gmail.com> Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com> Backpatch-through: 19 Discussion: https://postgr.es/m/20260710045217.f0.noahmisch@microsoft.com
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/19/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/19/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.