From 5cbe935c9d6046f5600ff2e083b4bae6ee1f4aa2 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Thu, 4 Jul 2013 11:11:56 -0400
Subject: [PATCH] docs: Clarify flag dependencies for background workers.

BGWORKER_BACKEND_DATABASE_CONNECTION can only be used if
BGWORKER_SHMEM_ACCESS is also used.

Michael Paquier, with some tweaks by me.
---
 doc/src/sgml/bgworker.sgml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/bgworker.sgml b/doc/src/sgml/bgworker.sgml
index 1151161a84..b0dde7564d 100644
--- a/doc/src/sgml/bgworker.sgml
+++ b/doc/src/sgml/bgworker.sgml
@@ -64,7 +64,10 @@ typedef struct BackgroundWorker
    <literal>BGWORKER_SHMEM_ACCESS</literal> (requesting shared memory access)
    and <literal>BGWORKER_BACKEND_DATABASE_CONNECTION</literal> (requesting the
    ability to establish a database connection, through which it can later run
-   transactions and queries).
+   transactions and queries). A background worker using
+   <literal>BGWORKER_BACKEND_DATABASE_CONNECTION</literal> to connect to
+   a database must also attach shared memory using
+   <literal>BGWORKER_SHMEM_ACCESS</literal>, or worker start-up will fail.
   </para>
 
   <para>