document that brin's autosummarize parameter is off by default
Hi everyone,
Just noted that the default value of autosummarize reloption for brin
indexes is not documented, or at least not well documented.
I added the default value in create_index.sgml where other options
mention their own defaults, also made a little change in brin.sgml to
make it more clear that is disabled by default (at least the way it
was written made no sense for me, but it could be that my english is
not that good).
--
Jaime Casanova
Director de Servicios Profesionales
SystemGuards - Consultores de PostgreSQL
Attachments:
brin_autosummarize_docs.patchtext/x-diff; charset=us-asciiDownload
diff --git a/doc/src/sgml/brin.sgml b/doc/src/sgml/brin.sgml
index d2f12bb605..5ac5d783d7 100644
--- a/doc/src/sgml/brin.sgml
+++ b/doc/src/sgml/brin.sgml
@@ -78,8 +78,8 @@
<function>brin_summarize_new_values(regclass)</function> functions;
automatically when <command>VACUUM</command> processes the table;
or by automatic summarization executed by autovacuum, as insertions
- occur. (This last trigger is disabled by default and can be enabled
- with the <literal>autosummarize</literal> parameter.)
+ occur (the latter is disabled by default and can be enabled
+ with the <literal>autosummarize</literal> parameter).
Conversely, a range can be de-summarized using the
<function>brin_desummarize_range(regclass, bigint)</function> function,
which is useful when the index tuple is no longer a very good
diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml
index cc484d5b39..9d92a6b837 100644
--- a/doc/src/sgml/ref/create_index.sgml
+++ b/doc/src/sgml/ref/create_index.sgml
@@ -563,7 +563,8 @@ CREATE [ UNIQUE ] INDEX [ CONCURRENTLY ] [ [ IF NOT EXISTS ] <replaceable class=
<listitem>
<para>
Defines whether a summarization run is invoked for the previous page
- range whenever an insertion is detected on the next one.
+ range whenever an insertion is detected on the next one. The default
+ is <literal>OFF</literal>.
</para>
</listitem>
</varlistentry>
Ten months ago, Jaime Casanova wrote:
Hi everyone,
Just noted that the default value of autosummarize reloption for brin
indexes is not documented, or at least not well documented.I added the default value in create_index.sgml where other options
mention their own defaults, also made a little change in brin.sgml to
make it more clear that is disabled by default (at least the way it
was written made no sense for me, but it could be that my english is
not that good).
It seems like "This last trigger" in the current text is intended to mean "The
second condition". Your change improves that.
Should we also consider enabling autosummarize by default ?
It was added in v10, after BRIN was added in v9.5. For us, brin wasn't usable
without autosummarize.
Also, note that vacuums are now triggered by insertions, since v13, so it might
be that autosummarize is needed much less.
--
Justin
PS. I hope there's a faster response to your pg_upgrade patch.