Doc: clarify enable_indexscan=off also disabled Index Only Scans

Disabling enable_indexscan has always also disabled Index Only Scans.
Here we make that more clear in the documentation in an attempt to
prevent future complaints complaining about this expected behavior.

Reported-by: Melanie Plageman
Author: David G. Johnston, David Rowley
Backpatch-through: 12, oldest supported version
Discussion: https://postgr.es/m/CAAKRu_atV=kovgpaLREyG68PB5+ncKvJ2UNoeRetEgyC3Yb5Sw@mail.gmail.com
This commit is contained in:
David Rowley 2024-10-29 16:24:10 +13:00
parent 49a23441ca
commit dda781609f

View File

@ -5442,8 +5442,9 @@ 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 index-scan and
index-only-scan plan types. The default is <literal>on</literal>.
Also see <xref linkend="guc-enable-indexonlyscan"/>.
</para>
</listitem>
</varlistentry>
@ -5458,7 +5459,9 @@ ANY <replaceable class="parameter">num_sync</replaceable> ( <replaceable class="
<para>
Enables or disables 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>. The
<xref linkend="guc-enable-indexscan"/> setting must also be
enabled to have the query planner consider index-only-scans.
</para>
</listitem>
</varlistentry>