From: Bruce Momjian <bruce@momjian.us>
Date: Tue, 6 Sep 2011 02:08:14 +0000 (-0400)
Subject: Add C comment about why we send cache invalidation messages for
X-Git-Tag: REL9_2_BETA1~1139
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=f458c90bff45ecae91fb55ef2b938af37d977af3;p=postgresql

Add C comment about why we send cache invalidation messages for
session-local objects.
---

diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
index 337fe64e10..98dc3adf30 100644
--- a/src/backend/utils/cache/inval.c
+++ b/src/backend/utils/cache/inval.c
@@ -812,6 +812,10 @@ ProcessCommittedInvalidationMessages(SharedInvalidationMessage *msgs,
  * about CurrentCmdInvalidMsgs too, since those changes haven't touched
  * the caches yet.
  *
+ * We still send invalidation messages for session-local objects to other
+ * backends because, while other backends cannot see any tuples, they can
+ * drop tables that are session-local to another session.
+ * 
  * In any case, reset the various lists to empty.  We need not physically
  * free memory here, since TopTransactionContext is about to be emptied
  * anyway.