From 25fe8b5f1ac93c3ec01519854e4f554b2e57a926 Mon Sep 17 00:00:00 2001
From: Robert Haas
Date: Fri, 8 Apr 2016 11:14:56 -0400
Subject: Add a 'parallel_degree' reloption.

The code that estimates what parallel degree should be uesd for the
scan of a relation is currently rather stupid, so add a parallel_degree
reloption that can be used to override the planner's rather limited
judgement.

Julien Rouhaud, reviewed by David Rowley, James Sewell, Amit Kapila,
and me.  Some further hacking by me.
---
 doc/src/sgml/ref/create_table.sgml | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'doc/src')

diff --git a/doc/src/sgml/ref/create_table.sgml b/doc/src/sgml/ref/create_table.sgml
index cd234dbf4e3..d1807ed0dbf 100644
--- a/doc/src/sgml/ref/create_table.sgml
+++ b/doc/src/sgml/ref/create_table.sgml
@@ -908,6 +908,19 @@ CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXI
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term><literal>parallel_degree</> (<type>integer</>)</term>
+    <listitem>
+     <para>
+      The parallel degree for a table is the number of workers that should
+      be used to assist a parallel scan of that table.  If not set, the
+      system will determine a value based on the relation size.  The actual
+      number of workers chosen by the planner may be less, for example due to
+      the setting of <xref linkend="guc-max-parallel-degree">.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><literal>autovacuum_enabled</>, <literal>toast.autovacuum_enabled</literal> (<type>boolean</>)</term>
     <listitem>
-- 
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