Re: Conflict detection for update_deleted in logical replication

>
> Here is the V39 patch set which includes the following changes:
>

Few trivial comments:

1)
Currently we have this error and detail:

ERROR: Enabling retain_conflict_info requires "wal_level" >= "replica"
DETAIL: A replication slot must be created to retain conflict information.

Shall we change it to something like:

msg: "wal_level is insufficient to create slot required by retain_conflict_info"
hint: "wal_level must be set to replica or logical at server start"

2)

+ <para>
+ Note that commit timestamps and origin data are not preserved during the
+ upgrade. Consequently, even with
+ <link linkend="sql-createsubscription-params-with-retain-conflict-info"><literal>retain_conflict_info</literal></link>
+ enabled, the upgraded subscriber might be unable to detect conflicts or log
+ relevant commit timestamps and origins when applying changes from the
+ publisher occurring before or during the upgrade. To prevent this
issue, the
+ user must ensure that all potentially conflicting changes are fully
+ replicated to the subscriber before proceeding with the upgrade.
+ </para>

Shall we have a NOTE tag here? This page has existing NOTE and WARNING
tags for similar situations where we are advising something to users?

thanks
Shveta