Re: Clean up some elog messages and comments for do_pg_stop_backup and do_pg_start_backup

On 2018-Dec-21, Michael Paquier wrote:

> The thing is that the current messages are actually misleading, because
> for base backups taken by the replication protocol pg_stop_backup is
> never called, which is I think confusing. While looking around I have
> also noticed that the top comments of do_pg_start_backup and
> do_pg_stop_backup also that they are used with BASE_BACKUP.
>
> Attached is a patch to reduce the confusion and improve the related
> comments and messages.

Looks like good cleanup.

This phrase: "Backup can be canceled safely, " seems a bit odd. It
would work either in plural "Backups can" or maybe be specific to the
current backup, "The backup can". But looking at the bigger picture,

errhint("Check that your archive_command is executing properly. "
+ "Backup can be canceled safely, "
"but the database backup will not be usable without all the WAL segments.")))

I think repeating the same term in the third line is not great. Some
ideas:

Backups can be canceled safely, but they will not be usable without all the WAL segments.
The backup can be canceled safely, but it will not be usable without all the WAL segments.
Database backups can be canceled safely, but the current backup will not be usable without all the WAL segments.
Database backups can be canceled safely, but no backup will be usable without all the WAL segments.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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