RE: Logical replication is missing block of rows when sending initial sync?

Dear Horiguchi-san,

> I'm not well-versed in the details of logical replication, but does
> logical replication inherently operate in such a way that it fully
> maintains relationships between tables? If not, isn't it possible that
> the issue in question is not about missing referenced data, but merely
> a temporary delay?

I assumed that tuples referred by FK existed before synchronization or during that.
In this case, IIUC the status is never 'r' before they are replicated. Thought?

Dear Depesz,

Is above assumption right?

Also, I suggest you that pg_stat_replicaiton can be checked on publisher when you
meet the failure again. If pg_stat_replication.replay_lsn is much behind
pg_stat_replication.sent_lsn, the replication may be delayed so that the tuples
are not appeared. pg_stat_subscription on subscriber has similar infos with replay_lsn.

Note that pg_stat_replication may be not updated if feedbacks from a subscriber
is disabled.

https://www.postgresql.org/docs/14/monitoring-stats.html#MONITORING-PG-STAT-SUBSCRIPTION

Best Regards,
Hayato Kuroda
FUJITSU LIMITED