On 2021/04/22 9:25, Kyotaro Horiguchi wrote:
What about the following description?
-------------------
When you are using -X none, if write activity on the primary is low,
pg_basebackup may need to wait a long time for all WAL files required
for
the backup to be archived. It may be useful to run pg_switch_wal
on the primary in order to trigger an immediate WAL file switch and
archiving.
-------------------
Looks far better.
Patch attached. I appended the following description to assist
users to understand why pg_basebackup may need wait a long time
when write activity is low on the primary.
------------------
pg_basebackup cannot force the standby to switch to
a new WAL file at the end of backup.
------------------
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
diff --git a/doc/src/sgml/ref/pg_basebackup.sgml
b/doc/src/sgml/ref/pg_basebackup.sgml
index a3e292d44a..9e6807b457 100644
--- a/doc/src/sgml/ref/pg_basebackup.sgml
+++ b/doc/src/sgml/ref/pg_basebackup.sgml
@@ -83,8 +83,14 @@ PostgreSQL documentation
</listitem>
<listitem>
<para>
- If you are using <literal>-X none</literal>, there is no guarantee that
all
- WAL files required for the backup are archived at the end of backup.
+ <application>pg_basebackup</application> cannot force the standby
+ to switch to a new WAL file at the end of backup.
+ When you are using <literal>-X none</literal>, if write activity on
+ the primary is low, <application>pg_basebackup</application> may
+ need to wait a long time for the last WAL file required for the backup
+ to be switched and archived. In this case, it may be useful to run
+ <function>pg_switch_wal</function> on the primary in order to
+ trigger an immediate WAL file switch.
</para>
</listitem>
<listitem>
