From ab6eaee88420db58a948849d5a735997728d73a9 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Mon, 4 Dec 2017 15:23:36 -0500
Subject: When VACUUM or ANALYZE skips a concurrently dropped table, log it.
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Hopefully, the additional logging will help avoid confusion that
could otherwise result.

Nathan Bossart, reviewed by Michael Paquier, Fabrízio Mello, and me
---
 src/backend/commands/analyze.c | 46 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 41 insertions(+), 5 deletions(-)

(limited to 'src/backend/commands/analyze.c')

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 760d19142ec..f952b3c7328 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -120,6 +120,7 @@ analyze_rel(Oid relid, RangeVar *relation, int options,
 	int			elevel;
 	AcquireSampleRowsFunc acquirefunc = NULL;
 	BlockNumber relpages = 0;
+	bool		rel_lock = true;
 
 	/* Select logging level */
 	if (options & VACOPT_VERBOSE)
@@ -149,15 +150,50 @@ analyze_rel(Oid relid, RangeVar *relation, int options,
 	else
 	{
 		onerel = NULL;
-		if (relation &&
-			IsAutoVacuumWorkerProcess() && params->log_min_duration >= 0)
-			ereport(LOG,
+		rel_lock = false;
+	}
+
+	/*
+	 * If we failed to open or lock the relation, emit a log message before
+	 * exiting.
+	 */
+	if (!onerel)
+	{
+		/*
+		 * If the RangeVar is not defined, we do not have enough information
+		 * to provide a meaningful log statement.  Chances are that
+		 * analyze_rel's caller has intentionally not provided this
+		 * information so that this logging is skipped, anyway.
+		 */
+		if (relation == NULL)
+			return;
+
+		/*
+		 * Determine the log level.  For autovacuum logs, we emit a LOG if
+		 * log_autovacuum_min_duration is not disabled.  For manual ANALYZE,
+		 * we emit a WARNING to match the log statements in the permissions
+		 * checks.
+		 */
+		if (!IsAutoVacuumWorkerProcess())
+			elevel = WARNING;
+		else if (params->log_min_duration >= 0)
+			elevel = LOG;
+		else
+			return;
+
+		if (!rel_lock)
+			ereport(elevel,
 					(errcode(ERRCODE_LOCK_NOT_AVAILABLE),
 					 errmsg("skipping analyze of \"%s\" --- lock not available",
 							relation->relname)));
-	}
-	if (!onerel)
+		else
+			ereport(elevel,
+					(errcode(ERRCODE_UNDEFINED_TABLE),
+					 errmsg("skipping analyze of \"%s\" --- relation no longer exists",
+							relation->relname)));
+
 		return;
+	}
 
 	/*
 	 * Check permissions --- this should match vacuum's check!
-- 
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