On Thu, Mar 26, 2026 at 01:28:16PM +1300, David Rowley wrote:
> A review:

Thanks.  I believe I've addressed all your feedback.

-- 
nathan
>From bf5d0ffc742ce744deb18ed91b8ce844b013eed5 Mon Sep 17 00:00:00 2001
From: Nathan Bossart <[email protected]>
Date: Wed, 25 Mar 2026 16:07:11 -0500
Subject: [PATCH v17 1/1] Add rudimentary table prioritization to autovacuum.

Autovacuum workers scan pg_class twice to collect the set of tables
to process.  The first pass is for plain relations and materialized
views, and the second is for TOAST tables.  When the worker finds a
table to process, it adds it to the end of a list.  Later on, it
processes the tables in the same order as the list.  This simple
strategy has worked surprisingly well for a long time, but there
have been many discussions over the years about trying to make it
better.

This commit introduces a scoring system that is used to sort the
aforementioned list of tables to process.  The idea is to have
autovacuum workers prioritize tables that are furthest beyond their
thresholds (e.g., a table nearing transaction ID wraparound should
be vacuumed first).  This prioritization scheme is certainly far
from perfect; there are simply too many possibilities for any
scoring technique to work across all workloads, and the situation
might change significantly between the time we calculate the score
and the time that autovacuum processes it.  However, we have
attemped to develop something that is expected to work for a large
portion of workloads with reasonable parameter settings.

The score is calculated as the maximum of the ratios of each of the
table's relevant values to its threshold.  For example, if the
number of inserted tuples is 100, and the insert threshold for the
table is 80, the insert score is 1.25.  If all other scores are
below that value, the table's score will be 1.25.  The other
criteria considered for the score are the table ages (both
relfrozenxid and relminmxid) compared to the corresponding
freeze-max-age setting, the number of update/deleted tuples
compared to the vacuum threshold, and the number of
inserted/updated/deleted tuples compared to the analyze threshold.

Once exception to the previous paragraph is for tables nearing
wraparound, i.e., those that have surpassed the effective failsafe
ages.  In that case, the relfrozenxid/relminmxid-based score is
scaled aggressively so that the table has a decent chance of
sorting to the front of the list.

To adjust how strongly each component contributes to the score, the
following parameters can be adjusted from their default of 1.0 to
anywhere between 0.0 and 10.0 (inclusive).  Setting all of these to
0.0 restores pre-v19 prioritization behavior:

        autovacuum_freeze_score_weight
        autovacuum_multixact_freeze_score_weight
        autovacuum_vacuum_score_weight
        autovacuum_vacuum_insert_score_weight
        autovacuum_analyze_score_weight

This is intended to be a baby step towards smarter autovacuum
workers.  Possible future improvements include, but are not limited
to, periodic reprioritization, automatic cost limit adjustments,
and better observability (e.g., a system view that shows current
scores).  While we do not expect this commit to produce
earth-shattering improvements, it should in theory produce marginal
ones, and it is arguably a prerequisite for the aforementioned
follow-up changes.

Reviewed-by: Sami Imseih <[email protected]>
Reviewed-by: David Rowley <[email protected]>
Reviewed-by: Robert Haas <[email protected]>
Reviewed-by: wenhui qiu <[email protected]>
Reviewed-by: Greg Burd <[email protected]>
Reviewed-by: Bharath Rupireddy <[email protected]>
Discussion: https://postgr.es/m/aOaAuXREwnPZVISO%40nathan
---
 doc/src/sgml/config.sgml                      |  90 ++++++
 doc/src/sgml/maintenance.sgml                 | 103 +++++++
 src/backend/postmaster/autovacuum.c           | 283 +++++++++++++++---
 src/backend/utils/misc/guc_parameters.dat     |  40 +++
 src/backend/utils/misc/postgresql.conf.sample |   5 +
 src/include/postmaster/autovacuum.h           |   6 +-
 src/tools/pgindent/typedefs.list              |   2 +
 7 files changed, 481 insertions(+), 48 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 8cdd826fbd3..229f41353eb 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -9395,6 +9395,96 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH 
csv;
        </listitem>
       </varlistentry>
 
+      <varlistentry id="guc-autovacuum-freeze-score-weight" 
xreflabel="autovacuum_freeze_score_weight">
+       <term><varname>autovacuum_freeze_score_weight</varname> (<type>floating 
point</type>)
+       <indexterm>
+        <primary><varname>autovacuum_freeze_score_weight</varname></primary>
+        <secondary>configuration parameter</secondary>
+       </indexterm>
+       </term>
+       <listitem>
+        <para>
+         Specifies the scaling factor of the transaction ID age component of
+         the score used by autovacuum for prioritization purposes.  The default
+         is <literal>1.0</literal>.  This parameter can only be set in the
+         <filename>postgresql.conf</filename> file or on the server command
+         line.  See <xref linkend="autovacuum-priority"/> for more information.
+        </para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry id="guc-autovacuum-multixact-freeze-score-weight" 
xreflabel="autovacuum_multixact_freeze_score_weight">
+       <term><varname>autovacuum_multixact_freeze_score_weight</varname> 
(<type>floating point</type>)
+       <indexterm>
+        
<primary><varname>autovacuum_multixact_freeze_score_weight</varname></primary>
+        <secondary>configuration parameter</secondary>
+       </indexterm>
+       </term>
+       <listitem>
+        <para>
+         Specifies the scaling factor of the multixact ID age component of the
+         score used by autovacuum for prioritization purposes.  The default is
+         <literal>1.0</literal>.  This parameter can only be set in the
+         <filename>postgresql.conf</filename> file or on the server command
+         line.  See <xref linkend="autovacuum-priority"/> for more information.
+        </para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry id="guc-autovacuum-vacuum-score-weight" 
xreflabel="autovacuum_vacuum_score_weight">
+       <term><varname>autovacuum_vacuum_score_weight</varname> (<type>floating 
point</type>)
+       <indexterm>
+        <primary><varname>autovacuum_vacuum_score_weight</varname></primary>
+        <secondary>configuration parameter</secondary>
+       </indexterm>
+       </term>
+       <listitem>
+        <para>
+         Specifies the scaling factor of the vacuum threshold component of the
+         score used by autovacuum for prioritization purposes.  The default is
+         <literal>1.0</literal>.  This parameter can only be set in the
+         <filename>postgresql.conf</filename> file or on the server command
+         line.  See <xref linkend="autovacuum-priority"/> for more information.
+        </para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry id="guc-autovacuum-vacuum-insert-score-weight" 
xreflabel="autovacuum_vacuum_insert_score_weight">
+       <term><varname>autovacuum_vacuum_insert_score_weight</varname> 
(<type>floating point</type>)
+       <indexterm>
+        
<primary><varname>autovacuum_vacuum_insert_score_weight</varname></primary>
+        <secondary>configuration parameter</secondary>
+       </indexterm>
+       </term>
+       <listitem>
+        <para>
+         Specifies the scaling factor of the vacuum insert threshold component
+         of the score used by autovacuum for prioritization purposes.  The
+         default is <literal>1.0</literal>.  This parameter can only be set in
+         the <filename>postgresql.conf</filename> file or on the server command
+         line.  See <xref linkend="autovacuum-priority"/> for more information.
+        </para>
+       </listitem>
+      </varlistentry>
+
+      <varlistentry id="guc-autovacuum-analyze-score-weight" 
xreflabel="autovacuum_analyze_score_weight">
+       <term><varname>autovacuum_analyze_score_weight</varname> 
(<type>floating point</type>)
+       <indexterm>
+        <primary><varname>autovacuum_analyze_score_weight</varname></primary>
+        <secondary>configuration parameter</secondary>
+       </indexterm>
+       </term>
+       <listitem>
+        <para>
+         Specifies the scaling factor of the analyze threshold component of the
+         score used by autovacuum for prioritization purposes.  The default is
+         <literal>1.0</literal>.  This parameter can only be set in the
+         <filename>postgresql.conf</filename> file or on the server command
+         line.  See <xref linkend="autovacuum-priority"/> for more information.
+        </para>
+       </listitem>
+      </varlistentry>
+
      </variablelist>
     </sect2>
 
diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml
index 75c22405a09..0d2a28207ed 100644
--- a/doc/src/sgml/maintenance.sgml
+++ b/doc/src/sgml/maintenance.sgml
@@ -1062,6 +1062,109 @@ analyze threshold = analyze base threshold + analyze 
scale factor * number of tu
      effectively prevent autovacuums from ever completing.
     </para>
    </warning>
+
+   <sect3 id="autovacuum-priority">
+    <title>Autovacuum Prioritization</title>
+
+    <para>
+     Autovacuum decides what to process in two steps: first it chooses a
+     database, then it chooses the tables within that database.  The autovacuum
+     launcher process prioritizes databases at risk of transaction ID or
+     multixact ID wraparound, else it chooses the database processed least
+     recently.  As an exception, it skips databases with no connections or no
+     activity since the last statistics reset, unless at risk of wraparound.
+    </para>
+
+    <para>
+     Within a database, the autovacuum worker process builds a list of tables
+     that require vacuum or analyze and sorts them using a scoring system.  It
+     scores each table by taking the maximum value of several component scores
+     representing various criteria important to vacuum or analyze.  Those
+     components are as follows:
+    </para>
+
+    <itemizedlist>
+     <listitem>
+      <para>
+       The <emphasis>transaction ID</emphasis> component measures the age in
+       transactions of the table's
+       
<structname>pg_class</structname>.<structfield>relfrozenxid</structfield>
+       field as compared to <xref linkend="guc-autovacuum-freeze-max-age"/>.
+       Furthermore, this component increases greatly once the age surpasses
+       <xref linkend="guc-vacuum-failsafe-age"/>.  The final value for this
+       component can be adjusted via
+       <xref linkend="guc-autovacuum-freeze-score-weight"/>.  Note that
+       increasing this parameter's value also lowers the age at which this
+       component begins scaling aggressively, i.e., the scaling age is divided
+       by its value if greater than <literal>1.0</literal>.
+      </para>
+     </listitem>
+
+     <listitem>
+      <para>
+       The <emphasis>multixact ID</emphasis> component measures the age in
+       multixacts of the table's
+       <structname>pg_class</structname>.<structfield>relminmxid</structfield>
+       field as compared to
+       <xref linkend="guc-autovacuum-multixact-freeze-max-age"/>.  Furthermore,
+       this component increases greatly once the age surpasses
+       <xref linkend="guc-vacuum-multixact-failsafe-age"/>.  The final value
+       for this component can be adjusted via
+       <xref linkend="guc-autovacuum-multixact-freeze-score-weight"/>.  Note
+       that increasing this parameter's value also lowers the age at which this
+       component begins scaling aggressively, i.e., the scaling age is divided
+       by its value if greater than <literal>1.0</literal>.
+      </para>
+     </listitem>
+
+     <listitem>
+      <para>
+       The <emphasis>vacuum</emphasis> component measures the number of updated
+       or deleted tuples as compared to the threshold calculated with
+       <xref linkend="guc-autovacuum-vacuum-threshold"/>,
+       <xref linkend="guc-autovacuum-vacuum-scale-factor"/>, and
+       <xref linkend="guc-autovacuum-vacuum-max-threshold"/>.  The final value
+       for this component can be adjusted via
+       <xref linkend="guc-autovacuum-vacuum-score-weight"/>.
+      </para>
+     </listitem>
+
+     <listitem>
+      <para>
+       The <emphasis>vacuum insert</emphasis> component measures the number of
+       inserted tuples as compared to the threshold calculated with
+       <xref linkend="guc-autovacuum-vacuum-insert-threshold"/> and
+       <xref linkend="guc-autovacuum-vacuum-insert-scale-factor"/>.  The final
+       value for this component can be adjusted via
+       <xref linkend="guc-autovacuum-vacuum-insert-score-weight"/>.
+      </para>
+     </listitem>
+
+     <listitem>
+      <para>
+       The <emphasis>analyze</emphasis> component measures the number of
+       inserted, updated, or deleted tuples as compared to the threshold
+       calculated with
+       <xref linkend="guc-autovacuum-analyze-threshold"/> and
+       <xref linkend="guc-autovacuum-analyze-scale-factor"/>.  The final value
+       for this component can be adjusted via
+       <xref linkend="guc-autovacuum-analyze-score-weight"/>.
+      </para>
+     </listitem>
+    </itemizedlist>
+
+    <para>
+     To revert to the prioritization strategy used before
+     <productname>PostgreSQL</productname> 19 (i.e., the order the tables are
+     listed in the <literal>pg_class</literal> system catalog), set all of the
+     aforementioned "weight" parameters to <literal>0.0</literal>.  Otherwise,
+     these "weight" parameters are multiplied to their respective component
+     scores.  For example, raising
+     <xref linkend="guc-autovacuum-analyze-score-weight"/> to
+     <literal>2.0</literal> effectively doubles the
+     <emphasis>analyze</emphasis> component score.
+    </para>
+   </sect3>
   </sect2>
  </sect1>
 
diff --git a/src/backend/postmaster/autovacuum.c 
b/src/backend/postmaster/autovacuum.c
index 7ecb069c248..d695f1de4bd 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -62,6 +62,7 @@
  */
 #include "postgres.h"
 
+#include <math.h>
 #include <signal.h>
 #include <sys/time.h>
 #include <unistd.h>
@@ -130,7 +131,11 @@ int                        autovacuum_anl_thresh;
 double         autovacuum_anl_scale;
 int                    autovacuum_freeze_max_age;
 int                    autovacuum_multixact_freeze_max_age;
-
+double         autovacuum_freeze_score_weight = 1.0;
+double         autovacuum_multixact_freeze_score_weight = 1.0;
+double         autovacuum_vacuum_score_weight = 1.0;
+double         autovacuum_vacuum_insert_score_weight = 1.0;
+double         autovacuum_analyze_score_weight = 1.0;
 double         autovacuum_vac_cost_delay;
 int                    autovacuum_vac_cost_limit;
 
@@ -311,6 +316,30 @@ static AutoVacuumShmemStruct *AutoVacuumShmem;
 static dlist_head DatabaseList = DLIST_STATIC_INIT(DatabaseList);
 static MemoryContext DatabaseListCxt = NULL;
 
+/*
+ * This struct is used by relation_needs_vacanalyze() to return the table's
+ * score (i.e., the maximum of the component scores) as well as the component
+ * scores themselves.
+ */
+typedef struct
+{
+       double          max;                    /* maximum of all values below 
*/
+       double          xid;                    /* transaction ID component */
+       double          mxid;                   /* multixact ID component */
+       double          vac;                    /* vacuum component */
+       double          vac_ins;                /* vacuum insert component */
+       double          anl;                    /* analyze component */
+} AutoVacuumScores;
+
+/*
+ * This struct is used to track and sort the list of tables to process.
+ */
+typedef struct
+{
+       Oid                     oid;
+       double          score;
+} TableToProcess;
+
 /*
  * Dummy pointer to persuade Valgrind that we've not leaked the array of
  * avl_dbase structs.  Make it global to ensure the compiler doesn't
@@ -349,7 +378,8 @@ static void relation_needs_vacanalyze(Oid relid, 
AutoVacOpts *relopts,
                                                                          
Form_pg_class classForm,
                                                                          
PgStat_StatTabEntry *tabentry,
                                                                          int 
effective_multixact_freeze_max_age,
-                                                                         bool 
*dovacuum, bool *doanalyze, bool *wraparound);
+                                                                         bool 
*dovacuum, bool *doanalyze, bool *wraparound,
+                                                                         
AutoVacuumScores *scores);
 
 static void autovacuum_do_vac_analyze(autovac_table *tab,
                                                                          
BufferAccessStrategy bstrategy);
@@ -1866,6 +1896,19 @@ get_database_list(void)
        return dblist;
 }
 
+/*
+ * List comparator for TableToProcess.  Note that this sorts the tables based
+ * on their scores in descending order.
+ */
+static int
+TableToProcessComparator(const ListCell *a, const ListCell *b)
+{
+       TableToProcess *t1 = (TableToProcess *) lfirst(a);
+       TableToProcess *t2 = (TableToProcess *) lfirst(b);
+
+       return (t2->score < t1->score) ? -1 : (t2->score > t1->score) ? 1 : 0;
+}
+
 /*
  * Process a database table-by-table
  *
@@ -1879,7 +1922,7 @@ do_autovacuum(void)
        HeapTuple       tuple;
        TableScanDesc relScan;
        Form_pg_database dbForm;
-       List       *table_oids = NIL;
+       List       *tables_to_process = NIL;
        List       *orphan_oids = NIL;
        HASHCTL         ctl;
        HTAB       *table_toast_map;
@@ -1991,6 +2034,7 @@ do_autovacuum(void)
                bool            dovacuum;
                bool            doanalyze;
                bool            wraparound;
+               AutoVacuumScores scores;
 
                if (classForm->relkind != RELKIND_RELATION &&
                        classForm->relkind != RELKIND_MATVIEW)
@@ -2031,11 +2075,18 @@ do_autovacuum(void)
                /* Check if it needs vacuum or analyze */
                relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
                                                                  
effective_multixact_freeze_max_age,
-                                                                 &dovacuum, 
&doanalyze, &wraparound);
+                                                                 &dovacuum, 
&doanalyze, &wraparound,
+                                                                 &scores);
 
-               /* Relations that need work are added to table_oids */
+               /* Relations that need work are added to tables_to_process */
                if (dovacuum || doanalyze)
-                       table_oids = lappend_oid(table_oids, relid);
+               {
+                       TableToProcess *table = palloc_object(TableToProcess);
+
+                       table->oid = relid;
+                       table->score = scores.max;
+                       tables_to_process = lappend(tables_to_process, table);
+               }
 
                /*
                 * Remember TOAST associations for the second pass.  Note: we 
must do
@@ -2091,6 +2142,7 @@ do_autovacuum(void)
                bool            dovacuum;
                bool            doanalyze;
                bool            wraparound;
+               AutoVacuumScores scores;
 
                /*
                 * We cannot safely process other backends' temp tables, so 
skip 'em.
@@ -2123,11 +2175,18 @@ do_autovacuum(void)
 
                relation_needs_vacanalyze(relid, relopts, classForm, tabentry,
                                                                  
effective_multixact_freeze_max_age,
-                                                                 &dovacuum, 
&doanalyze, &wraparound);
+                                                                 &dovacuum, 
&doanalyze, &wraparound,
+                                                                 &scores);
 
                /* ignore analyze for toast tables */
                if (dovacuum)
-                       table_oids = lappend_oid(table_oids, relid);
+               {
+                       TableToProcess *table = palloc_object(TableToProcess);
+
+                       table->oid = relid;
+                       table->score = scores.max;
+                       tables_to_process = lappend(tables_to_process, table);
+               }
 
                /* Release stuff to avoid leakage */
                if (free_relopts)
@@ -2251,6 +2310,19 @@ do_autovacuum(void)
                MemoryContextSwitchTo(AutovacMemCxt);
        }
 
+       /*
+        * In case list_sort() would modify the list even when all the scores 
are
+        * 0.0, skip sorting if all the weight parameters are set to 0.0.  This 
is
+        * probably not necessary, but we want to ensure folks have a guaranteed
+        * escape hatch from the scoring system.
+        */
+       if (autovacuum_freeze_score_weight != 0.0 ||
+               autovacuum_multixact_freeze_score_weight != 0.0 ||
+               autovacuum_vacuum_score_weight != 0.0 ||
+               autovacuum_vacuum_insert_score_weight != 0.0 ||
+               autovacuum_analyze_score_weight != 0.0)
+               list_sort(tables_to_process, TableToProcessComparator);
+
        /*
         * Optionally, create a buffer access strategy object for VACUUM to use.
         * We use the same BufferAccessStrategy object for all tables VACUUMed 
by
@@ -2279,9 +2351,9 @@ do_autovacuum(void)
        /*
         * Perform operations on collected tables.
         */
-       foreach(cell, table_oids)
+       foreach_ptr(TableToProcess, table, tables_to_process)
        {
-               Oid                     relid = lfirst_oid(cell);
+               Oid                     relid = table->oid;
                HeapTuple       classTup;
                autovac_table *tab;
                bool            isshared;
@@ -2512,7 +2584,7 @@ deleted:
                pg_atomic_test_set_flag(&MyWorkerInfo->wi_dobalance);
        }
 
-       list_free(table_oids);
+       list_free_deep(tables_to_process);
 
        /*
         * Perform additional work items, as requested by backends.
@@ -2913,6 +2985,7 @@ recheck_relation_needs_vacanalyze(Oid relid,
                                                                  bool 
*wraparound)
 {
        PgStat_StatTabEntry *tabentry;
+       AutoVacuumScores scores;
 
        /* fetch the pgstat table entry */
        tabentry = pgstat_fetch_stat_tabentry_ext(classForm->relisshared,
@@ -2920,15 +2993,12 @@ recheck_relation_needs_vacanalyze(Oid relid,
 
        relation_needs_vacanalyze(relid, avopts, classForm, tabentry,
                                                          
effective_multixact_freeze_max_age,
-                                                         dovacuum, doanalyze, 
wraparound);
+                                                         dovacuum, doanalyze, 
wraparound,
+                                                         &scores);
 
        /* Release tabentry to avoid leakage */
        if (tabentry)
                pfree(tabentry);
-
-       /* ignore ANALYZE for toast tables */
-       if (classForm->relkind == RELKIND_TOASTVALUE)
-               *doanalyze = false;
 }
 
 /*
@@ -2969,6 +3039,47 @@ recheck_relation_needs_vacanalyze(Oid relid,
  * autovacuum_vacuum_threshold GUC variable.  Similarly, a vac_scale_factor
  * value < 0 is substituted with the value of
  * autovacuum_vacuum_scale_factor GUC variable.  Ditto for analyze.
+ *
+ * This function also returns scores that can be used to sort the list of
+ * tables to process.  The idea is to have autovacuum prioritize tables that
+ * are furthest beyond their thresholds (e.g., a table nearing transaction ID
+ * wraparound should be vacuumed first).  This prioritization scheme is
+ * certainly far from perfect; there are simply too many possibilities for any
+ * scoring technique to work across all workloads, and the situation might
+ * change significantly between the time we calculate the score and the time
+ * that autovacuum processes it.  However, we have attempted to develop
+ * something that is expected to work for a large portion of workloads with
+ * reasonable parameter settings.
+ *
+ * The autovacuum table score is calculated as the maximum of the ratios of
+ * each of the table's relevant values to its threshold.  For example, if the
+ * number of inserted tuples is 100, and the insert threshold for the table is
+ * 80, the insert score is 1.25.  If all other scores are below that value, the
+ * returned score will be 1.25.  The other criteria considered for the score
+ * are the table ages (both relfrozenxid and relminmxid) compared to the
+ * corresponding freeze-max-age setting, the number of updated/deleted tuples
+ * compared to the vacuum threshold, and the number of inserted/updated/deleted
+ * tuples compared to the analyze threshold.
+ *
+ * One exception to the previous paragraph is for tables nearing wraparound,
+ * i.e., those that have surpassed the effective failsafe ages.  In that case,
+ * the relfrozen/relminmxid-based score is scaled aggressively so that the
+ * table has a decent chance of sorting to the front of the list.
+ *
+ * To adjust how strongly each component contributes to the score, the
+ * following parameters can be adjusted from their default of 1.0 to anywhere
+ * between 0.0 and 10.0 (inclusive).  Setting all of these to 0.0 restores
+ * pre-v19 prioritization behavior:
+ *
+ *     autovacuum_freeze_score_weight
+ *     autovacuum_multixact_freeze_score_weight
+ *     autovacuum_vacuum_score_weight
+ *     autovacuum_vacuum_insert_score_weight
+ *     autovacuum_analyze_score_weight
+ *
+ * The autovacuum table score is returned in scores->max.  The component scores
+ * are also returned in the "scores" argument via the other members of the
+ * AutoVacuumScores struct.
  */
 static void
 relation_needs_vacanalyze(Oid relid,
@@ -2979,7 +3090,8 @@ relation_needs_vacanalyze(Oid relid,
  /* output params below */
                                                  bool *dovacuum,
                                                  bool *doanalyze,
-                                                 bool *wraparound)
+                                                 bool *wraparound,
+                                                 AutoVacuumScores *scores)
 {
        bool            force_vacuum;
        bool            av_enabled;
@@ -3008,11 +3120,16 @@ relation_needs_vacanalyze(Oid relid,
        int                     multixact_freeze_max_age;
        TransactionId xidForceLimit;
        TransactionId relfrozenxid;
+       MultiXactId relminmxid;
        MultiXactId multiForceLimit;
 
        Assert(classForm != NULL);
        Assert(OidIsValid(relid));
 
+       memset(scores, 0, sizeof(AutoVacuumScores));
+       *dovacuum = false;
+       *doanalyze = false;
+
        /*
         * Determine vacuum/analyze equation parameters.  We have two possible
         * sources: the passed reloptions (which could be a main table or a 
toast
@@ -3060,17 +3177,17 @@ relation_needs_vacanalyze(Oid relid,
 
        av_enabled = (relopts ? relopts->enabled : true);
 
+       relfrozenxid = classForm->relfrozenxid;
+       relminmxid = classForm->relminmxid;
+
        /* Force vacuum if table is at risk of wraparound */
        xidForceLimit = recentXid - freeze_max_age;
        if (xidForceLimit < FirstNormalTransactionId)
                xidForceLimit -= FirstNormalTransactionId;
-       relfrozenxid = classForm->relfrozenxid;
        force_vacuum = (TransactionIdIsNormal(relfrozenxid) &&
                                        TransactionIdPrecedes(relfrozenxid, 
xidForceLimit));
        if (!force_vacuum)
        {
-               MultiXactId relminmxid = classForm->relminmxid;
-
                multiForceLimit = recentMulti - multixact_freeze_max_age;
                if (multiForceLimit < FirstMultiXactId)
                        multiForceLimit -= FirstMultiXactId;
@@ -3079,13 +3196,65 @@ relation_needs_vacanalyze(Oid relid,
        }
        *wraparound = force_vacuum;
 
+       /* Update the score. */
+       if (force_vacuum)
+       {
+               uint32          xid_age;
+               uint32          mxid_age;
+               int                     effective_xid_failsafe_age;
+               int                     effective_mxid_failsafe_age;
+
+               /*
+                * To calculate the (M)XID age portion of the score, divide the 
age by
+                * its respective *_freeze_max_age parameter.
+                */
+               xid_age = TransactionIdIsNormal(relfrozenxid) ? recentXid - 
relfrozenxid : 0;
+               mxid_age = MultiXactIdIsValid(relminmxid) ? recentMulti - 
relminmxid : 0;
+
+               scores->xid = (double) xid_age / freeze_max_age;
+               scores->mxid = (double) mxid_age / multixact_freeze_max_age;
+
+               /*
+                * To ensure tables are given increased priority once they begin
+                * approaching wraparound, we scale the score aggressively if 
the ages
+                * surpass vacuum_failsafe_age or vacuum_multixact_failsafe_age.
+                *
+                * As in vacuum_xid_failsafe_check(), the effective failsafe 
age is no
+                * less than 105% the value of the respective *_freeze_max_age
+                * parameter.  Note that per-table settings could result in a 
low
+                * score even if the table surpasses the failsafe settings.  
However,
+                * this is a strange enough corner case that we don't bother 
trying to
+                * handle it.
+                *
+                * We further adjust the effective failsafe ages with the weight
+                * parameters so that increasing them lowers the ages at which 
we
+                * begin scaling aggressively.
+                */
+               effective_xid_failsafe_age = Max(vacuum_failsafe_age,
+                                                                               
 autovacuum_freeze_max_age * 1.05);
+               effective_mxid_failsafe_age = Max(vacuum_multixact_failsafe_age,
+                                                                               
  autovacuum_multixact_freeze_max_age * 1.05);
+
+               if (autovacuum_freeze_score_weight > 1.0)
+                       effective_xid_failsafe_age /= 
autovacuum_freeze_score_weight;
+               if (autovacuum_multixact_freeze_score_weight > 1.0)
+                       effective_mxid_failsafe_age /= 
autovacuum_multixact_freeze_score_weight;
+
+               if (xid_age >= effective_xid_failsafe_age)
+                       scores->xid = pow(scores->xid, Max(1.0, (double) 
xid_age / 100000000));
+               if (mxid_age >= effective_mxid_failsafe_age)
+                       scores->mxid = pow(scores->mxid, Max(1.0, (double) 
mxid_age / 100000000));
+
+               scores->xid *= autovacuum_freeze_score_weight;
+               scores->mxid *= autovacuum_multixact_freeze_score_weight;
+
+               scores->max = Max(scores->xid, scores->mxid);
+               *dovacuum = true;
+       }
+
        /* User disabled it in pg_class.reloptions?  (But ignore if at risk) */
        if (!av_enabled && !force_vacuum)
-       {
-               *doanalyze = false;
-               *dovacuum = false;
                return;
-       }
 
        /*
         * If we found stats for the table, and autovacuum is currently enabled,
@@ -3134,34 +3303,54 @@ relation_needs_vacanalyze(Oid relid,
                        vac_ins_scale_factor * reltuples * pcnt_unfrozen;
                anlthresh = (float4) anl_base_thresh + anl_scale_factor * 
reltuples;
 
+               /*
+                * Determine if this table needs vacuum, and update the score 
if it
+                * does.
+                */
+               if (vactuples > vacthresh)
+               {
+                       scores->vac = (double) vactuples / Max(vacthresh, 1);
+                       scores->vac *= autovacuum_vacuum_score_weight;
+                       scores->max = Max(scores->max, scores->vac);
+                       *dovacuum = true;
+               }
+
+               if (vac_ins_base_thresh >= 0 && instuples > vacinsthresh)
+               {
+                       scores->vac_ins = (double) instuples / 
Max(vacinsthresh, 1);
+                       scores->vac_ins *= 
autovacuum_vacuum_insert_score_weight;
+                       scores->max = Max(scores->max, scores->vac_ins);
+                       *dovacuum = true;
+               }
+
+               /*
+                * Determine if this table needs analyze, and update the score 
if it
+                * does.  Note that we don't analyze TOAST tables and 
pg_statistic.
+                */
+               if (anltuples > anlthresh &&
+                       relid != StatisticRelationId &&
+                       classForm->relkind != RELKIND_TOASTVALUE)
+               {
+                       scores->anl = (double) anltuples / Max(anlthresh, 1);
+                       scores->anl *= autovacuum_analyze_score_weight;
+                       scores->max = Max(scores->max, scores->anl);
+                       *doanalyze = true;
+               }
+
                if (vac_ins_base_thresh >= 0)
-                       elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), ins: %.0f 
(threshold %.0f), anl: %.0f (threshold %.0f)",
+                       elog(DEBUG3, "%s: vac: %.0f (thresh %.0f, score %.2f), 
ins: %.0f (thresh %.0f, score %.2f), anl: %.0f (thresh %.0f, score %.2f), xid 
score: %.2f, mxid score: %.2f",
                                 NameStr(classForm->relname),
-                                vactuples, vacthresh, instuples, vacinsthresh, 
anltuples, anlthresh);
+                                vactuples, vacthresh, scores->vac,
+                                instuples, vacinsthresh, scores->vac_ins,
+                                anltuples, anlthresh, scores->anl,
+                                scores->xid, scores->mxid);
                else
-                       elog(DEBUG3, "%s: vac: %.0f (threshold %.0f), ins: 
(disabled), anl: %.0f (threshold %.0f)",
+                       elog(DEBUG3, "%s: vac: %.0f (thresh %.0f, score %.2f), 
ins: (disabled), anl: %.0f (thresh %.0f, score %.2f), xid score: %.2f, mxid 
score: %.2f",
                                 NameStr(classForm->relname),
-                                vactuples, vacthresh, anltuples, anlthresh);
-
-               /* Determine if this table needs vacuum or analyze. */
-               *dovacuum = force_vacuum || (vactuples > vacthresh) ||
-                       (vac_ins_base_thresh >= 0 && instuples > vacinsthresh);
-               *doanalyze = (anltuples > anlthresh);
+                                vactuples, vacthresh, scores->vac,
+                                anltuples, anlthresh, scores->anl,
+                                scores->xid, scores->mxid);
        }
-       else
-       {
-               /*
-                * Skip a table not found in stat hash, unless we have to force 
vacuum
-                * for anti-wrap purposes.  If it's not acted upon, there's no 
need to
-                * vacuum it.
-                */
-               *dovacuum = force_vacuum;
-               *doanalyze = false;
-       }
-
-       /* ANALYZE refuses to work with pg_statistic */
-       if (relid == StatisticRelationId)
-               *doanalyze = false;
 }
 
 /*
diff --git a/src/backend/utils/misc/guc_parameters.dat 
b/src/backend/utils/misc/guc_parameters.dat
index 0c9854ad8fc..0a862693fcd 100644
--- a/src/backend/utils/misc/guc_parameters.dat
+++ b/src/backend/utils/misc/guc_parameters.dat
@@ -136,6 +136,14 @@
   max => '100.0',
 },
 
+{ name => 'autovacuum_analyze_score_weight', type => 'real', context => 
'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
+  short_desc => 'Scaling factor of analyze score for autovacuum 
prioritization.',
+  variable => 'autovacuum_analyze_score_weight',
+  boot_val => '1.0',
+  min => '0.0',
+  max => '10.0',
+},
+
 { name => 'autovacuum_analyze_threshold', type => 'int', context => 
'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
   short_desc => 'Minimum number of tuple inserts, updates, or deletes prior to 
analyze.',
   variable => 'autovacuum_anl_thresh',
@@ -154,6 +162,14 @@
   max => '2000000000',
 },
 
+{ name => 'autovacuum_freeze_score_weight', type => 'real', context => 
'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
+  short_desc => 'Scaling factor of freeze score for autovacuum 
prioritization.',
+  variable => 'autovacuum_freeze_score_weight',
+  boot_val => '1.0',
+  min => '0.0',
+  max => '10.0',
+},
+
 { name => 'autovacuum_max_workers', type => 'int', context => 'PGC_SIGHUP', 
group => 'VACUUM_AUTOVACUUM',
   short_desc => 'Sets the maximum number of simultaneously running autovacuum 
worker processes.',
   variable => 'autovacuum_max_workers',
@@ -171,6 +187,14 @@
   max => '2000000000',
 },
 
+{ name => 'autovacuum_multixact_freeze_score_weight', type => 'real', context 
=> 'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
+  short_desc => 'Scaling factor of multixact freeze score for autovacuum 
prioritization.',
+  variable => 'autovacuum_multixact_freeze_score_weight',
+  boot_val => '1.0',
+  min => '0.0',
+  max => '10.0',
+},
+
 { name => 'autovacuum_naptime', type => 'int', context => 'PGC_SIGHUP', group 
=> 'VACUUM_AUTOVACUUM',
   short_desc => 'Time to sleep between autovacuum runs.',
   flags => 'GUC_UNIT_S',
@@ -207,6 +231,14 @@
   max => '100.0',
 },
 
+{ name => 'autovacuum_vacuum_insert_score_weight', type => 'real', context => 
'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
+  short_desc => 'Scaling factor of vacuum insert score for autovacuum 
prioritization.',
+  variable => 'autovacuum_vacuum_insert_score_weight',
+  boot_val => '1.0',
+  min => '0.0',
+  max => '10.0',
+},
+
 { name => 'autovacuum_vacuum_insert_threshold', type => 'int', context => 
'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
   short_desc => 'Minimum number of tuple inserts prior to vacuum.',
   long_desc => '-1 disables insert vacuums.',
@@ -233,6 +265,14 @@
   max => '100.0',
 },
 
+{ name => 'autovacuum_vacuum_score_weight', type => 'real', context => 
'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
+  short_desc => 'Scaling factor of vacuum score for autovacuum 
prioritization.',
+  variable => 'autovacuum_vacuum_score_weight',
+  boot_val => '1.0',
+  min => '0.0',
+  max => '10.0',
+},
+
 { name => 'autovacuum_vacuum_threshold', type => 'int', context => 
'PGC_SIGHUP', group => 'VACUUM_AUTOVACUUM',
   short_desc => 'Minimum number of tuple updates or deletes prior to vacuum.',
   variable => 'autovacuum_vac_thresh',
diff --git a/src/backend/utils/misc/postgresql.conf.sample 
b/src/backend/utils/misc/postgresql.conf.sample
index e4abe6c0077..cf15597385b 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -733,6 +733,11 @@
 #autovacuum_multixact_freeze_max_age = 400000000        # maximum multixact age
                                                         # before forced vacuum
                                                         # (change requires 
restart)
+#autovacuum_freeze_score_weight = 1.0           # range 0.0-10.0
+#autovacuum_multixact_freeze_score_weight = 1.0 # range 0.0-10.0
+#autovacuum_vacuum_score_weight = 1.0           # range 0.0-10.0
+#autovacuum_vacuum_insert_score_weight = 1.0    # range 0.0-10.0
+#autovacuum_analyze_score_weight = 1.0          # range 0.0-10.0
 #autovacuum_vacuum_cost_delay = 2ms     # default vacuum cost delay for
                                         # autovacuum, in milliseconds;
                                         # -1 means use vacuum_cost_delay
diff --git a/src/include/postmaster/autovacuum.h 
b/src/include/postmaster/autovacuum.h
index 5aa0f3a8ac1..b21d111d4d5 100644
--- a/src/include/postmaster/autovacuum.h
+++ b/src/include/postmaster/autovacuum.h
@@ -43,7 +43,11 @@ extern PGDLLIMPORT int autovacuum_freeze_max_age;
 extern PGDLLIMPORT int autovacuum_multixact_freeze_max_age;
 extern PGDLLIMPORT double autovacuum_vac_cost_delay;
 extern PGDLLIMPORT int autovacuum_vac_cost_limit;
-
+extern PGDLLIMPORT double autovacuum_freeze_score_weight;
+extern PGDLLIMPORT double autovacuum_multixact_freeze_score_weight;
+extern PGDLLIMPORT double autovacuum_vacuum_score_weight;
+extern PGDLLIMPORT double autovacuum_vacuum_insert_score_weight;
+extern PGDLLIMPORT double autovacuum_analyze_score_weight;
 extern PGDLLIMPORT int Log_autovacuum_min_duration;
 extern PGDLLIMPORT int Log_autoanalyze_min_duration;
 
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index decc9f7a572..a05b30dab5a 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -187,6 +187,7 @@ AuthToken
 AutoPrewarmReadStreamData
 AutoPrewarmSharedState
 AutoVacOpts
+AutoVacuumScores
 AutoVacuumShmemStruct
 AutoVacuumWorkItem
 AutoVacuumWorkItemType
@@ -3098,6 +3099,7 @@ TableScanDesc
 TableScanDescData
 TableSpaceCacheEntry
 TableSpaceOpts
+TableToProcess
 TablespaceList
 TablespaceListCell
 TapeBlockTrailer
-- 
2.50.1 (Apple Git-155)

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