On Mon, Oct 21, 2024 at 7:20 PM David Rowley <dgrowle...@gmail.com> wrote:
> On Tue, 22 Oct 2024 at 14:46, David G. Johnston
> <david.g.johns...@gmail.com> wrote:
> > We should probably at least improve the documentation in 19.17.1; this
> interaction is apparently not self-evident.
>
> Yeah, I agree. The documentation could better reflect the current
> behaviour.
>
> Do you want to submit that in patch form?
>
>
Went with a slightly different wording that seems to flow better with the
xrefs I added between the two options.
David J.
From 8b9be4096352088ea22f114e68041fd09ee6e28c Mon Sep 17 00:00:00 2001
From: "David G. Johnston" <david.g.johns...@gmail.com>
Date: Tue, 22 Oct 2024 17:25:27 -0700
Subject: [PATCH] doc: Cross reference enable_indexscan and
enable_indexonlyscan
Document that enable_indexscan controls the inclusion of all (normal
and index-only) index scan plan node types. Note that index-only scans
can be independently disabled.
Note the implication of this in enable_indexonlyscan, that a setting of
"on" is ignored when all index scans types are disabled.
Left unwritten is the absence of a symmetric option to exclude normal
index scans while allowing index-only scans.
---
doc/src/sgml/config.sgml | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 934ef5e469..04cbe7ac34 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -5415,8 +5415,10 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
</term>
<listitem>
<para>
- Enables or disables the query planner's use of index-scan plan
- types. The default is <literal>on</literal>.
+ Enables or disables the query planner's use of all index-scan related plan
+ types. The default is <literal>on</literal>. The index-only-scan plan types
+ can be independently disabled by setting <xref linkend="guc-enable-indexonlyscan"/>
+ to <literal>off</literal>.
</para>
</listitem>
</varlistentry>
@@ -5429,9 +5431,10 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
</term>
<listitem>
<para>
- Enables or disables the query planner's use of index-only-scan plan
+ Set to <literal>off</literal> to disable the query planner's use of index-only-scan plan
types (see <xref linkend="indexes-index-only-scans"/>).
- The default is <literal>on</literal>.
+ The default is <literal>on</literal>. However, this setting has no effect if
+ <xref linkend="guc-enable-indexscan"/> is set to <literal>off</literal>.
</para>
</listitem>
</varlistentry>
--
2.34.1
