On Mon, Jul 18, 2022 at 07:39:55PM -0700, David G. Johnston wrote:
> On Mon, Jul 18, 2022 at 6:27 PM Japin Li <japi...@hotmail.com> wrote:
>
>
> +0.90
>
> Consider changing:
>
> "makes any base backups taken before this unusable"
>
> to:
>
> "makes existing base backups unusable"
>
> As I try to justify this, though, it isn't quite true, maybe:
>
> "makes point-in-time recovery, using existing base backups, unable to replay
> future WAL."
I went with simpler wording.
--
Bruce Momjian <br...@momjian.us> https://momjian.us
EDB https://enterprisedb.com
Indecision is a decision. Inaction is an action. Mark Batterson
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 37fd80388c..c2bdacb6a7 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2764,9 +2764,10 @@ include_dir 'conf.d'
levels. This parameter can only be set at server start.
</para>
<para>
- In <literal>minimal</literal> level, no information is logged for
- permanent relations for the remainder of a transaction that creates or
- rewrites them. This can make operations much faster (see
+ The <literal>minimal</literal> level generates the least WAL
+ volume. It logs no row information for permanent relations
+ in transactions that create or
+ rewrite them. This can make operations much faster (see
<xref linkend="populate-pitr"/>). Operations that initiate this
optimization include:
<simplelist>
@@ -2778,19 +2779,20 @@ include_dir 'conf.d'
<member><command>REINDEX</command></member>
<member><command>TRUNCATE</command></member>
</simplelist>
- But minimal WAL does not contain enough information to reconstruct the
- data from a base backup and the WAL logs, so <literal>replica</literal> or
- higher must be used to enable WAL archiving
- (<xref linkend="guc-archive-mode"/>) and streaming replication.
+ However, minimal WAL does not contain sufficient information for
+ point-in-time recovery, so <literal>replica</literal> or
+ higher must be used to enable continuous archiving
+ (<xref linkend="guc-archive-mode"/>) and streaming binary replication.
+ In fact, the server will not even start in this mode if
+ <varname>max_wal_senders</varname> is non-zero.
Note that changing <varname>wal_level</varname> to
- <literal>minimal</literal> makes any base backups taken before
- unavailable for archive recovery and standby server, which may
- lead to data loss.
+ <literal>minimal</literal> makes previous base backups unusable
+ for point-in-time recovery and standby servers.
</para>
<para>
In <literal>logical</literal> level, the same information is logged as
- with <literal>replica</literal>, plus information needed to allow
- extracting logical change sets from the WAL. Using a level of
+ with <literal>replica</literal>, plus information needed to
+ extract logical change sets from the WAL. Using a level of
<literal>logical</literal> will increase the WAL volume, particularly if many
tables are configured for <literal>REPLICA IDENTITY FULL</literal> and
many <command>UPDATE</command> and <command>DELETE</command> statements are
