Add mode and started_by columns to pg_stat_progress_vacuum view.

The new columns, mode and started_by, indicate the vacuum
mode ('normal', 'aggressive', or 'failsafe') and the initiator of the
vacuum ('manual', 'autovacuum', or 'autovacuum_wraparound'),
respectively. This allows users and monitoring tools to better
understand VACUUM behavior.

Bump catalog version.

Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Robert Treat <rob@xzilla.net>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Yu Wang <wangyu_runtime@163.com>
Discussion: https://postgr.es/m/CAOzEurQcOY-OBL_ouEVfEaFqe_md3vB5pXjR_m6L71Dcp1JKCQ@mail.gmail.com

doc/src/sgml/maintenance.sgml

@@ -1018,8 +1018,11 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu
     see <xref linkend="table-lock-compatibility"/>.  However, if the autovacuum
     is running to prevent transaction ID wraparound (i.e., the autovacuum query
     name in the <structname>pg_stat_activity</structname> view ends with
-    <literal>(to prevent wraparound)</literal>), the autovacuum is not
+    <literal>(to prevent wraparound)</literal> or the
-    automatically interrupted.
+    <structfield>started_by</structfield> column in the
+    <structname>pg_stat_progress_vacuum</structname> view shows
+    <literal>autovacuum_wraparound</literal> value), the autovacuum is
+    not automatically interrupted.
    </para>
 
    <warning>

doc/src/sgml/monitoring.sgml

@@ -6710,6 +6710,81 @@ FROM pg_stat_get_backend_idset() AS backendid;
        stale.
       </para></entry>
      </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>mode</structfield> <type>text</type>
+      </para>
+      <para>
+       The mode in which the current <command>VACUUM</command> operation is
+       running. See <xref linkend="vacuum-for-wraparound"/> for details of each
+       mode. Possible values are:
+       <itemizedlist>
+        <listitem>
+         <para>
+          <literal>normal</literal>: The operation is performing a standard
+          vacuum. It is neither required to run in aggressive mode nor operating
+          in failsafe mode.
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <literal>aggressive</literal>: The operation is running an aggressive
+          vacuum, which must scan every page that is not marked all-frozen.
+          The parameters <xref linkend="guc-vacuum-freeze-table-age"/> and
+          <xref linkend="guc-vacuum-multixact-freeze-table-age"/> determine when a
+          table requires aggressive vacuuming.
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <literal>failsafe</literal>: The vacuum has entered failsafe mode,
+          in which it performs only the minimum work necessary to avoid
+          transaction ID or multixact ID wraparound failure.
+          The parameters <xref linkend="guc-vacuum-failsafe-age"/> and
+          <xref linkend="guc-vacuum-multixact-failsafe-age"/> determine when the
+          vacuum enters failsafe mode. The vacuum may start in this mode or
+          switch to it while running; the value of the
+          <structfield>mode</structfield> column may transition from another
+          mode to <literal>failsafe</literal> during the operation.
+         </para>
+        </listitem>
+       </itemizedlist>
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>started_by</structfield> <type>text</type>
+      </para>
+      <para>
+       Shows what caused the current <command>VACUUM</command> operation to be
+       started. Possible values are:
+       <itemizedlist>
+        <listitem>
+         <para>
+          <literal>manual</literal>: The vacuum was started by an explicit
+          <command>VACUUM</command> command.
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <literal>autovacuum</literal>: The vacuum was started by an autovacuum
+          worker. Vacuums run by autovacuum workers may be interrupted due to
+          lock conflicts.
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <literal>autovacuum_wraparound</literal>: The vacuum was started by an
+          autovacuum worker to prevent transaction ID or multixact ID
+          wraparound. Vacuums run for wraparound protection are not interrupted
+          due to lock conflicts.
+         </para>
+        </listitem>
+       </itemizedlist>
+      </para></entry>
+     </row>
     </tbody>
    </tgroup>
   </table>

src/backend/access/heap/vacuumlazy.c

@@ -664,6 +664,14 @@ heap_vacuum_rel(Relation rel, const VacuumParams params,
 
 	pgstat_progress_start_command(PROGRESS_COMMAND_VACUUM,
 								  RelationGetRelid(rel));
+	if (AmAutoVacuumWorkerProcess())
+		pgstat_progress_update_param(PROGRESS_VACUUM_STARTED_BY,
+									 params.is_wraparound
+									 ? PROGRESS_VACUUM_STARTED_BY_AUTOVACUUM_WRAPAROUND
+									 : PROGRESS_VACUUM_STARTED_BY_AUTOVACUUM);
+	else
+		pgstat_progress_update_param(PROGRESS_VACUUM_STARTED_BY,
+									 PROGRESS_VACUUM_STARTED_BY_MANUAL);
 
 	/*
 	 * Setup error traceback support for ereport() first.  The idea is to set
@@ -820,6 +828,12 @@ heap_vacuum_rel(Relation rel, const VacuumParams params,
 	 */
 	heap_vacuum_eager_scan_setup(vacrel, params);
 
+	/* Report the vacuum mode: 'normal' or 'aggressive' */
+	pgstat_progress_update_param(PROGRESS_VACUUM_MODE,
+								 vacrel->aggressive
+								 ? PROGRESS_VACUUM_MODE_AGGRESSIVE
+								 : PROGRESS_VACUUM_MODE_NORMAL);
+
 	if (verbose)
 	{
 		if (vacrel->aggressive)
@@ -3001,9 +3015,10 @@ lazy_check_wraparound_failsafe(LVRelState *vacrel)
 	{
 		const int	progress_index[] = {
 			PROGRESS_VACUUM_INDEXES_TOTAL,
-			PROGRESS_VACUUM_INDEXES_PROCESSED
+			PROGRESS_VACUUM_INDEXES_PROCESSED,
+			PROGRESS_VACUUM_MODE
 		};
-		int64		progress_val[2] = {0, 0};
+		int64		progress_val[3] = {0, 0, PROGRESS_VACUUM_MODE_FAILSAFE};
 
 		VacuumFailsafeActive = true;
 
@@ -3019,8 +3034,8 @@ lazy_check_wraparound_failsafe(LVRelState *vacrel)
 		vacrel->do_index_cleanup = false;
 		vacrel->do_rel_truncate = false;
 
-		/* Reset the progress counters */
+		/* Reset the progress counters and set the failsafe mode */
-		pgstat_progress_update_multi_param(2, progress_index, progress_val);
+		pgstat_progress_update_multi_param(3, progress_index, progress_val);
 
 		ereport(WARNING,
 				(errmsg("bypassing nonessential maintenance of table \"%s.%s.%s\" as a failsafe after %d index scans",

src/backend/catalog/system_views.sql

@@ -1268,7 +1268,15 @@ CREATE VIEW pg_stat_progress_vacuum AS
         S.param6 AS max_dead_tuple_bytes, S.param7 AS dead_tuple_bytes,
         S.param8 AS num_dead_item_ids, S.param9 AS indexes_total,
         S.param10 AS indexes_processed,
-        S.param11 / 1000000::double precision AS delay_time
+        S.param11 / 1000000::double precision AS delay_time,
+        CASE S.param12 WHEN 1 THEN 'normal'
+                       WHEN 2 THEN 'aggressive'
+                       WHEN 3 THEN 'failsafe'
+                       ELSE NULL END AS mode,
+        CASE S.param13 WHEN 1 THEN 'manual'
+                       WHEN 2 THEN 'autovacuum'
+                       WHEN 3 THEN 'autovacuum_wraparound'
+                       ELSE NULL END AS started_by
     FROM pg_stat_get_progress_info('VACUUM') AS S
         LEFT JOIN pg_database D ON S.datid = D.oid;
 

src/include/catalog/catversion.h

@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202512091
+#define CATALOG_VERSION_NO	202512092
 
 #endif

src/include/commands/progress.h

@@ -29,6 +29,8 @@
 #define PROGRESS_VACUUM_INDEXES_TOTAL			8
 #define PROGRESS_VACUUM_INDEXES_PROCESSED		9
 #define PROGRESS_VACUUM_DELAY_TIME				10
+#define PROGRESS_VACUUM_MODE					11
+#define PROGRESS_VACUUM_STARTED_BY				12
 
 /* Phases of vacuum (as advertised via PROGRESS_VACUUM_PHASE) */
 #define PROGRESS_VACUUM_PHASE_SCAN_HEAP			1
@@ -38,6 +40,16 @@
 #define PROGRESS_VACUUM_PHASE_TRUNCATE			5
 #define PROGRESS_VACUUM_PHASE_FINAL_CLEANUP		6
 
+/* Modes of vacuum (as advertised via PROGRESS_VACUUM_MODE) */
+#define PROGRESS_VACUUM_MODE_NORMAL				1
+#define PROGRESS_VACUUM_MODE_AGGRESSIVE			2
+#define PROGRESS_VACUUM_MODE_FAILSAFE			3
+
+/* Reasons for vacuum (as advertised via PROGRESS_VACUUM_STARTED_BY) */
+#define PROGRESS_VACUUM_STARTED_BY_MANUAL					1
+#define PROGRESS_VACUUM_STARTED_BY_AUTOVACUUM				2
+#define PROGRESS_VACUUM_STARTED_BY_AUTOVACUUM_WRAPAROUND	3
+
 /* Progress parameters for analyze */
 #define PROGRESS_ANALYZE_PHASE						0
 #define PROGRESS_ANALYZE_BLOCKS_TOTAL				1

src/test/regress/expected/rules.out

@@ -2105,7 +2105,19 @@ pg_stat_progress_vacuum| SELECT s.pid,
     s.param8 AS num_dead_item_ids,
     s.param9 AS indexes_total,
     s.param10 AS indexes_processed,
-    ((s.param11)::double precision / (1000000)::double precision) AS delay_time
+    ((s.param11)::double precision / (1000000)::double precision) AS delay_time,
+        CASE s.param12
+            WHEN 1 THEN 'normal'::text
+            WHEN 2 THEN 'aggressive'::text
+            WHEN 3 THEN 'failsafe'::text
+            ELSE NULL::text
+        END AS mode,
+        CASE s.param13
+            WHEN 1 THEN 'manual'::text
+            WHEN 2 THEN 'autovacuum'::text
+            WHEN 3 THEN 'autovacuum_wraparound'::text
+            ELSE NULL::text
+        END AS started_by
    FROM (pg_stat_get_progress_info('VACUUM'::text) s(pid, datid, relid, param1, param2, param3, param4, param5, param6, param7, param8, param9, param10, param11, param12, param13, param14, param15, param16, param17, param18, param19, param20)
      LEFT JOIN pg_database d ON ((s.datid = d.oid)));
 pg_stat_recovery_prefetch| SELECT stats_reset,