v9-0006-Skip-VACUUM-ANALYZE-with-VACOPT_SKIP_LOCKED-if-ex.patch

From 3674e267c86e39664d8281001a903b33eab8c9a9 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <bossartn@amazon.com>
Date: Wed, 5 Sep 2018 14:44:57 +0000
Subject: [PATCH v9 6/7] Skip VACUUM/ANALYZE with VACOPT_SKIP_LOCKED if
 expand_vacuum_rel() would block.

---
 src/backend/commands/vacuum.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 764559f043..07c509646f 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -528,7 +528,29 @@ expand_vacuum_rel(VacuumRelation *vrel, int options)
 		 * below, as well as find_all_inheritors's expectation that the caller
 		 * holds some lock on the starting relation.
 		 */
-		relid = RangeVarGetRelid(vrel->relation, AccessShareLock, false);
+		relid = RangeVarGetRelidExtended(vrel->relation,
+										 AccessShareLock,
+										 (options & VACOPT_SKIP_LOCKED) ? RVR_SKIP_LOCKED : 0,
+										 NULL, NULL);
+
+		/*
+		 * If the lock is unavailable, emit the same log statement that
+		 * vacuum_rel() and analyze_rel() would.
+		 */
+		if (!OidIsValid(relid))
+		{
+			if (options & VACOPT_VACUUM)
+				ereport(WARNING,
+						(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
+						 errmsg("skipping vacuum of \"%s\" --- lock not available",
+								vrel->relation->relname)));
+			else
+				ereport(WARNING,
+						(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
+						 errmsg("skipping analyze of \"%s\" --- lock not available",
+								vrel->relation->relname)));
+			return vacrels;
+		}
 
 		/*
 		 * To check whether the relation is a partitioned table and its
-- 
2.16.2