Hello Hayato! > Note that apply workers can stop due to some reasons (e.g., disabling subscriptions, > error out, deadlock...). In this case, the snapshot cannot eb registered by the > worker and index can be re-built during the period.
However, the xmin of a slot affects replication_slot_xmin in ProcArrayStruct, so it might be straightforward to wait for it during concurrent index builds. We could consider adding a separate conflict_resolution_replication_slot_xmin to wait only for that. > Anyway, this topic introduces huge complexity and is not mandatory for update_deleted > detection. We can work on it in later versions based on the needs. >From my perspective, this is critical for databases. REINDEX CONCURRENTLY is typically run in production databases on regular basic, so any master-master system should be unaffected by it. Best regards, Mikhail.
