From 27ccbb7af5d1e16da65c819b7fb93955395643d8 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <bossartn@amazon.com>
Date: Sun, 31 May 2020 21:29:39 +0000
Subject: [PATCH v4 1/1] Add MAIN_RELATION_CLEANUP and TOAST_TABLE_CLEANUP
 options to VACUUM.

---
 doc/src/sgml/ref/vacuum.sgml         | 28 +++++++++++++
 src/backend/commands/vacuum.c        | 76 +++++++++++++++++++++++++++---------
 src/backend/postmaster/autovacuum.c  |  2 +-
 src/bin/psql/tab-complete.c          |  5 ++-
 src/include/commands/vacuum.h        |  5 ++-
 src/test/regress/expected/vacuum.out | 10 +++++
 src/test/regress/sql/vacuum.sql      | 10 +++++
 7 files changed, 112 insertions(+), 24 deletions(-)

diff --git a/doc/src/sgml/ref/vacuum.sgml b/doc/src/sgml/ref/vacuum.sgml
index a48f75ad7b..3e15824eaa 100644
--- a/doc/src/sgml/ref/vacuum.sgml
+++ b/doc/src/sgml/ref/vacuum.sgml
@@ -33,6 +33,8 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet
     DISABLE_PAGE_SKIPPING [ <replaceable class="parameter">boolean</replaceable> ]
     SKIP_LOCKED [ <replaceable class="parameter">boolean</replaceable> ]
     INDEX_CLEANUP [ <replaceable class="parameter">boolean</replaceable> ]
+    MAIN_RELATION_CLEANUP [ <replaceable class="parameter">boolean</replaceable> ]
+    TOAST_TABLE_CLEANUP [ <replaceable class="parameter">boolean</replaceable> ]
     TRUNCATE [ <replaceable class="parameter">boolean</replaceable> ]
     PARALLEL <replaceable class="parameter">integer</replaceable>
 
@@ -210,6 +212,32 @@ VACUUM [ FULL ] [ FREEZE ] [ VERBOSE ] [ ANALYZE ] [ <replaceable class="paramet
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term><literal>MAIN_RELATION_CLEANUP</literal></term>
+    <listitem>
+     <para>
+      Specifies that <command>VACUUM</command> should attempt to process the
+      main relation.  This is normally the desired behavior and is the default.
+      Setting this option to false may be useful when it is necessary to only
+      vacuum a relation's corresponding <literal>TOAST</literal> table.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term><literal>TOAST_TABLE_CLEANUP</literal></term>
+    <listitem>
+     <para>
+      Specifies that <command>VACUUM</command> should attempt to process the
+      corresponding <literal>TOAST</literal> table for each relation, if one
+      exists.  This is normally the desired behavior and is the default.
+      Setting this option to false may be useful when it is necessary to only
+      vacuum the main relation.  This option cannot be disabled when the
+      <literal>FULL</literal> option is specified.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><literal>TRUNCATE</literal></term>
     <listitem>
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 5a110edb07..2cfd28f45c 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -84,7 +84,10 @@ static void vac_truncate_clog(TransactionId frozenXID,
 							  MultiXactId minMulti,
 							  TransactionId lastSaneFrozenXid,
 							  MultiXactId lastSaneMinMulti);
-static bool vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params);
+static bool vacuum_rel(Oid relid,
+					   RangeVar *relation,
+					   VacuumParams *params,
+					   bool processing_toast_table);
 static double compute_parallel_delay(void);
 static VacOptTernaryValue get_vacopt_ternary_value(DefElem *def);
 
@@ -104,6 +107,8 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
 	bool		freeze = false;
 	bool		full = false;
 	bool		disable_page_skipping = false;
+	bool		main_rel_cleanup = true;
+	bool		toast_cleanup = true;
 	ListCell   *lc;
 
 	/* Set default value */
@@ -140,6 +145,10 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
 			disable_page_skipping = defGetBoolean(opt);
 		else if (strcmp(opt->defname, "index_cleanup") == 0)
 			params.index_cleanup = get_vacopt_ternary_value(opt);
+		else if (strcmp(opt->defname, "main_relation_cleanup") == 0)
+			main_rel_cleanup = defGetBoolean(opt);
+		else if (strcmp(opt->defname, "toast_table_cleanup") == 0)
+			toast_cleanup = defGetBoolean(opt);
 		else if (strcmp(opt->defname, "truncate") == 0)
 			params.truncate = get_vacopt_ternary_value(opt);
 		else if (strcmp(opt->defname, "parallel") == 0)
@@ -189,13 +198,14 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
 		(analyze ? VACOPT_ANALYZE : 0) |
 		(freeze ? VACOPT_FREEZE : 0) |
 		(full ? VACOPT_FULL : 0) |
-		(disable_page_skipping ? VACOPT_DISABLE_PAGE_SKIPPING : 0);
+		(disable_page_skipping ? VACOPT_DISABLE_PAGE_SKIPPING : 0) |
+		(main_rel_cleanup ? VACOPT_MAIN_REL_CLEANUP : 0) |
+		(toast_cleanup ? VACOPT_TOAST_CLEANUP : 0);
 
 	/* sanity checks on options */
 	Assert(params.options & (VACOPT_VACUUM | VACOPT_ANALYZE));
 	Assert((params.options & VACOPT_VACUUM) ||
 		   !(params.options & (VACOPT_FULL | VACOPT_FREEZE)));
-	Assert(!(params.options & VACOPT_SKIPTOAST));
 
 	if ((params.options & VACOPT_FULL) && params.nworkers > 0)
 		ereport(ERROR,
@@ -318,6 +328,16 @@ vacuum(List *relations, VacuumParams *params,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("VACUUM option DISABLE_PAGE_SKIPPING cannot be used with FULL")));
 
+	/*
+	 * Sanity check TOAST_TABLE_CLEANUP option.
+	 */
+	if ((params->options & VACOPT_FULL) != 0 &&
+		(params->options & VACOPT_TOAST_CLEANUP) == 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("VACUUM option TOAST_TABLE_CLEANUP cannot be "
+						"disabled when FULL is specified")));
+
 	/*
 	 * Send info about dead objects to the statistics collector, unless we are
 	 * in autovacuum --- autovacuum.c does this for itself.
@@ -446,7 +466,7 @@ vacuum(List *relations, VacuumParams *params,
 
 			if (params->options & VACOPT_VACUUM)
 			{
-				if (!vacuum_rel(vrel->oid, vrel->relation, params))
+				if (!vacuum_rel(vrel->oid, vrel->relation, params, false))
 					continue;
 			}
 
@@ -1665,7 +1685,10 @@ vac_truncate_clog(TransactionId frozenXID,
  *		At entry and exit, we are not inside a transaction.
  */
 static bool
-vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
+vacuum_rel(Oid relid,
+		   RangeVar *relation,
+		   VacuumParams *params,
+		   bool processing_toast_table)
 {
 	LOCKMODE	lmode;
 	Relation	onerel;
@@ -1674,6 +1697,7 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 	Oid			save_userid;
 	int			save_sec_context;
 	int			save_nestlevel;
+	bool		process_toast;
 
 	Assert(params != NULL);
 
@@ -1841,9 +1865,16 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 	/*
 	 * Remember the relation's TOAST relation for later, if the caller asked
 	 * us to process it.  In VACUUM FULL, though, the toast table is
-	 * automatically rebuilt by cluster_rel so we shouldn't recurse to it.
+	 * automatically rebuilt by cluster_rel, so we shouldn't recurse to it
+	 * unless MAIN_RELATION_CLEANUP is disabled.
 	 */
-	if (!(params->options & VACOPT_SKIPTOAST) && !(params->options & VACOPT_FULL))
+	process_toast = (params->options & VACOPT_TOAST_CLEANUP) != 0;
+
+	if ((params->options & VACOPT_FULL) != 0 &&
+		(params->options & VACOPT_MAIN_REL_CLEANUP) != 0)
+		process_toast = false;
+
+	if (process_toast)
 		toast_relid = onerel->rd_rel->reltoastrelid;
 	else
 		toast_relid = InvalidOid;
@@ -1861,23 +1892,30 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 
 	/*
 	 * Do the actual work --- either FULL or "lazy" vacuum
+	 *
+	 * We skip this part if we're processing the main relation and
+	 * MAIN_RELATION_CLEANUP has been disabled.
 	 */
-	if (params->options & VACOPT_FULL)
+	if ((params->options & VACOPT_MAIN_REL_CLEANUP) != 0 ||
+		processing_toast_table)
 	{
-		int			cluster_options = 0;
+		if (params->options & VACOPT_FULL)
+		{
+			int			cluster_options = 0;
 
-		/* close relation before vacuuming, but hold lock until commit */
-		relation_close(onerel, NoLock);
-		onerel = NULL;
+			/* close relation before vacuuming, but hold lock until commit */
+			relation_close(onerel, NoLock);
+			onerel = NULL;
 
-		if ((params->options & VACOPT_VERBOSE) != 0)
-			cluster_options |= CLUOPT_VERBOSE;
+			if ((params->options & VACOPT_VERBOSE) != 0)
+				cluster_options |= CLUOPT_VERBOSE;
 
-		/* VACUUM FULL is now a variant of CLUSTER; see cluster.c */
-		cluster_rel(relid, InvalidOid, cluster_options);
+			/* VACUUM FULL is now a variant of CLUSTER; see cluster.c */
+			cluster_rel(relid, InvalidOid, cluster_options);
+		}
+		else
+			table_relation_vacuum(onerel, params, vac_strategy);
 	}
-	else
-		table_relation_vacuum(onerel, params, vac_strategy);
 
 	/* Roll back any GUC changes executed by index functions */
 	AtEOXact_GUC(false, save_nestlevel);
@@ -1903,7 +1941,7 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 	 * totally unimportant for toast relations.
 	 */
 	if (toast_relid != InvalidOid)
-		vacuum_rel(toast_relid, NULL, params);
+		vacuum_rel(toast_relid, NULL, params, true);
 
 	/*
 	 * Now release the session-level lock on the master table.
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index a8d4dfdd7c..e4f2402e5c 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2883,7 +2883,7 @@ table_recheck_autovac(Oid relid, HTAB *table_toast_map,
 		tab = palloc(sizeof(autovac_table));
 		tab->at_relid = relid;
 		tab->at_sharedrel = classForm->relisshared;
-		tab->at_params.options = VACOPT_SKIPTOAST |
+		tab->at_params.options = VACOPT_MAIN_REL_CLEANUP |
 			(dovacuum ? VACOPT_VACUUM : 0) |
 			(doanalyze ? VACOPT_ANALYZE : 0) |
 			(!wraparound ? VACOPT_SKIP_LOCKED : 0);
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index eb018854a5..e71df26096 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -3665,8 +3665,9 @@ psql_completion(const char *text, int start, int end)
 		if (ends_with(prev_wd, '(') || ends_with(prev_wd, ','))
 			COMPLETE_WITH("FULL", "FREEZE", "ANALYZE", "VERBOSE",
 						  "DISABLE_PAGE_SKIPPING", "SKIP_LOCKED",
-						  "INDEX_CLEANUP", "TRUNCATE", "PARALLEL");
-		else if (TailMatches("FULL|FREEZE|ANALYZE|VERBOSE|DISABLE_PAGE_SKIPPING|SKIP_LOCKED|INDEX_CLEANUP|TRUNCATE"))
+						  "INDEX_CLEANUP", "TRUNCATE", "PARALLEL",
+						  "MAIN_RELATION_CLEANUP", "TOAST_TABLE_CLEANUP");
+		else if (TailMatches("FULL|FREEZE|ANALYZE|VERBOSE|DISABLE_PAGE_SKIPPING|SKIP_LOCKED|INDEX_CLEANUP|TRUNCATE|MAIN_RELATION_CLEANUP|TOAST_TABLE_CLEANUP"))
 			COMPLETE_WITH("ON", "OFF");
 	}
 	else if (HeadMatches("VACUUM") && TailMatches("("))
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index a4cd721400..8a7e5b2aa1 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -182,8 +182,9 @@ typedef enum VacuumOption
 	VACOPT_FREEZE = 1 << 3,		/* FREEZE option */
 	VACOPT_FULL = 1 << 4,		/* FULL (non-concurrent) vacuum */
 	VACOPT_SKIP_LOCKED = 1 << 5,	/* skip if cannot get lock */
-	VACOPT_SKIPTOAST = 1 << 6,	/* don't process the TOAST table, if any */
-	VACOPT_DISABLE_PAGE_SKIPPING = 1 << 7	/* don't skip any pages */
+	VACOPT_TOAST_CLEANUP = 1 << 6,	/* process TOAST table, if any */
+	VACOPT_DISABLE_PAGE_SKIPPING = 1 << 7,	/* don't skip any pages */
+	VACOPT_MAIN_REL_CLEANUP = 1 << 8	/* process main relation */
 } VacuumOption;
 
 /*
diff --git a/src/test/regress/expected/vacuum.out b/src/test/regress/expected/vacuum.out
index 3fccb183c0..43cb9f25d4 100644
--- a/src/test/regress/expected/vacuum.out
+++ b/src/test/regress/expected/vacuum.out
@@ -252,6 +252,16 @@ RESET default_transaction_isolation;
 BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
 ANALYZE vactst;
 COMMIT;
+-- MAIN_RELATION_CLEANUP and TOAST_TABLE_CLEANUP options
+ALTER TABLE vactst ADD COLUMN t TEXT;
+ALTER TABLE vactst ALTER COLUMN t SET STORAGE EXTERNAL;
+VACUUM (MAIN_RELATION_CLEANUP FALSE, TOAST_TABLE_CLEANUP FALSE) vactst;
+VACUUM (MAIN_RELATION_CLEANUP FALSE, ANALYZE) vactst;
+VACUUM (TOAST_TABLE_CLEANUP FALSE, FULL) vactst;
+ERROR:  VACUUM option TOAST_TABLE_CLEANUP cannot be disabled when FULL is specified
+VACUUM (MAIN_RELATION_CLEANUP FALSE) vactst;
+VACUUM (TOAST_TABLE_CLEANUP FALSE) vactst;
+VACUUM (MAIN_RELATION_CLEANUP FALSE, FULL) vactst;
 DROP TABLE vaccluster;
 DROP TABLE vactst;
 DROP TABLE vacparted;
diff --git a/src/test/regress/sql/vacuum.sql b/src/test/regress/sql/vacuum.sql
index c7b5f96f6b..ba046e439b 100644
--- a/src/test/regress/sql/vacuum.sql
+++ b/src/test/regress/sql/vacuum.sql
@@ -213,6 +213,16 @@ BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
 ANALYZE vactst;
 COMMIT;
 
+-- MAIN_RELATION_CLEANUP and TOAST_TABLE_CLEANUP options
+ALTER TABLE vactst ADD COLUMN t TEXT;
+ALTER TABLE vactst ALTER COLUMN t SET STORAGE EXTERNAL;
+VACUUM (MAIN_RELATION_CLEANUP FALSE, TOAST_TABLE_CLEANUP FALSE) vactst;
+VACUUM (MAIN_RELATION_CLEANUP FALSE, ANALYZE) vactst;
+VACUUM (TOAST_TABLE_CLEANUP FALSE, FULL) vactst;
+VACUUM (MAIN_RELATION_CLEANUP FALSE) vactst;
+VACUUM (TOAST_TABLE_CLEANUP FALSE) vactst;
+VACUUM (MAIN_RELATION_CLEANUP FALSE, FULL) vactst;
+
 DROP TABLE vaccluster;
 DROP TABLE vactst;
 DROP TABLE vacparted;
-- 
2.16.6

