Add option PROCESS_TOAST to VACUUM

This option controls if toast tables associated with a relation are
vacuumed or not when running a manual VACUUM.  It was already possible
to trigger a manual VACUUM on a toast relation without processing its
main relation, but a manual vacuum on a main relation always forced a
vacuum on its toast table.  This is useful in scenarios where the level
of bloat or transaction age of the main and toast relations differs a
lot.

This option is an extension of the existing VACOPT_SKIPTOAST that was
used by autovacuum to control if toast relations should be skipped or
not.  This internal flag is renamed to VACOPT_PROCESS_TOAST for
consistency with the new option.

A new option switch, called --no-process-toast, is added to vacuumdb.

Author: Nathan Bossart
Reviewed-by: Kirk Jamison, Michael Paquier, Justin Pryzby
Discussion: https://postgr.es/m/BA8951E9-1524-48C5-94AF-73B1F0D7857F@amazon.com

1 files changed, 14 insertions, 3 deletions

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 462f9a0f822..0f77c5aff49 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -104,6 +104,7 @@ ExecVacuum(ParseState *pstate, VacuumStmt *vacstmt, bool isTopLevel)
 	bool		freeze = false;
 	bool		full = false;
 	bool		disable_page_skipping = false;
+	bool		process_toast = true;
 	ListCell   *lc;
 
 	/* Set default value */
@@ -140,6 +141,8 @@ 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, "process_toast") == 0)
+			process_toast = 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 +192,13 @@ 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) |
+		(process_toast ? VACOPT_PROCESS_TOAST : 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 +321,13 @@ vacuum(List *relations, VacuumParams *params,
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("VACUUM option DISABLE_PAGE_SKIPPING cannot be used with FULL")));
 
+	/* sanity check for PROCESS_TOAST */
+	if ((params->options & VACOPT_FULL) != 0 &&
+		(params->options & VACOPT_PROCESS_TOAST) == 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("PROCESS_TOAST required with VACUUM FULL")));
+
 	/*
 	 * Send info about dead objects to the statistics collector, unless we are
 	 * in autovacuum --- autovacuum.c does this for itself.
@@ -1895,7 +1905,8 @@ vacuum_rel(Oid relid, RangeVar *relation, VacuumParams *params)
 	 * us to process it.  In VACUUM FULL, though, the toast table is
 	 * automatically rebuilt by cluster_rel so we shouldn't recurse to it.
 	 */
-	if (!(params->options & VACOPT_SKIPTOAST) && !(params->options & VACOPT_FULL))
+	if ((params->options & VACOPT_PROCESS_TOAST) != 0 &&
+		(params->options & VACOPT_FULL) == 0)
 		toast_relid = onerel->rd_rel->reltoastrelid;
 	else
 		toast_relid = InvalidOid;