Alvaro Herrera wrote:
> Excerpts from Bruce Momjian's message of mar ago 02 22:46:55 -0400 2011:
>
> > I have created a documentation patch to clarify this, and to mention
> > CREATE TABLE AS which also has this optimization.
>
> It doesn't seem particularly better to me. How about something like
>
> In minimal level, WAL-logging of some operations can be safely skipped,
> which can make those operations much faster (see <blah>). Operations on
> which this optimization can be applied include:
> <simplelist>
> <item>CREATE INDEX</item>
> <item>CLUSTER</item>
> <item>CREATE TABLE AS</item>
> <item>COPY, when tables that were created or truncated in the same
> transaction
> </simplelist>
>
> Minimal WAL does not contain enough information to reconstruct the data
> from a base backup and the WAL logs, so either <literal>archive</> or
> <literal>hot_standby</> level must be used to enable ...
Good idea --- updated patch attached.
--
Bruce Momjian <[email protected]> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
new file mode 100644
index 4fadca9..aac6c3b
*** a/doc/src/sgml/config.sgml
--- b/doc/src/sgml/config.sgml
*************** SET ENABLE_SEQSCAN TO OFF;
*** 1451,1461 ****
This parameter can only be set at server start.
</para>
<para>
! In <literal>minimal</> level, WAL-logging of some bulk operations, like
! <command>CREATE INDEX</>, <command>CLUSTER</> and <command>COPY</> on
! a table that was created or truncated in the same transaction can be
! safely skipped, which can make those operations much faster (see
! <xref linkend="populate-pitr">). But minimal WAL does not contain
enough information to reconstruct the data from a base backup and the
WAL logs, so either <literal>archive</> or <literal>hot_standby</>
level must be used to enable
--- 1451,1468 ----
This parameter can only be set at server start.
</para>
<para>
! In <literal>minimal</> level, WAL-logging of some bulk
! operations can be safely skipped, which can make those
! operations much faster (see <xref linkend="populate-pitr">).
! Operations in which this optimization can be applied include:
! <simplelist>
! <item>CREATE INDEX</item>
! <item>CLUSTER</item>
! <item>CREATE TABLE AS</item>
! <item>COPY into tables that were created or truncated in the same
! transaction
! </simplelist>
! But minimal WAL does not contain
enough information to reconstruct the data from a base backup and the
WAL logs, so either <literal>archive</> or <literal>hot_standby</>
level must be used to enable
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