Still another try at stabilizing stats_ext test results.

The stats_ext test is not expecting that autovacuum will touch
any of its tables; an expectation falsified by commit b07642db.
Although I'm suspicious that there's something else going on that
makes extended stats estimates not 100% reproducible, it's pretty
easy to demonstrate that there are places in this test that fail
if an autovacuum updates the table's stats unexpectedly.

Hence, revert the band-aid changes made by 2dc16efe and 24566b35
in favor of summarily disabling autovacuum for all the tables that
this test checks estimated rowcounts for.

Also remove an evidently obsolete comment at the head of the test.

Discussion: https://postgr.es/m/15012.1585623298@sss.pgh.pa.us

src/test/regress/expected/stats_ext.out

 -- Generic extended statistics support
--- We will be checking execution plans without/with statistics, so
--- let's make sure we get simple non-parallel plans. Also set the
--- work_mem low so that we can use small amounts of data.
+--
+-- Note: tables for which we check estimated row counts should be created
+-- with autovacuum_enabled = off, so that we don't have unstable results
+-- from auto-analyze happening when we didn't expect it.
+--
 -- check the number of estimated/actual rows in the top node
 create function check_estimated_rows(text) returns table (estimated int, actual int)
 language plpgsql as
@@ -184,7 +186,8 @@ CREATE TABLE ndistinct (
     filler3 DATE,
     c INT,
     d INT
-);
+)
+WITH (autovacuum_enabled = off);
 -- over-estimates when using only per-column statistics
 INSERT INTO ndistinct (a, b, c, filler1)
      SELECT i/100, i/100, i/100, cash_words((i/100)::money)
@@ -279,7 +282,7 @@ INSERT INTO ndistinct (a, b, c, filler1)
      SELECT mod(i,50), mod(i,51), mod(i,32),
             cash_words(mod(i,33)::int::money)
        FROM generate_series(1,5000) s(i);
-VACUUM (ANALYZE) ndistinct;
+ANALYZE ndistinct;
 SELECT s.stxkind, d.stxdndistinct
   FROM pg_statistic_ext s, pg_statistic_ext_data d
  WHERE s.stxrelid = 'ndistinct'::regclass
@@ -369,13 +372,14 @@ CREATE TABLE functional_dependencies (
     filler3 DATE,
     c INT,
     d TEXT
-);
+)
+WITH (autovacuum_enabled = off);
 CREATE INDEX fdeps_ab_idx ON functional_dependencies (a, b);
 CREATE INDEX fdeps_abc_idx ON functional_dependencies (a, b, c);
 -- random data (no functional dependencies)
 INSERT INTO functional_dependencies (a, b, c, filler1)
      SELECT mod(i, 23), mod(i, 29), mod(i, 31), i FROM generate_series(1,5000) s(i);
-VACUUM (ANALYZE) functional_dependencies;
+ANALYZE functional_dependencies;
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
  estimated | actual 
 -----------+--------
@@ -408,7 +412,7 @@ TRUNCATE functional_dependencies;
 DROP STATISTICS func_deps_stat;
 INSERT INTO functional_dependencies (a, b, c, filler1)
      SELECT mod(i,100), mod(i,50), mod(i,25), i FROM generate_series(1,5000) s(i);
-VACUUM (ANALYZE) functional_dependencies;
+ANALYZE functional_dependencies;
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
  estimated | actual 
 -----------+--------
@@ -741,7 +745,7 @@ SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE
         25 |     50
 (1 row)
 
-VACUUM (ANALYZE) functional_dependencies;
+ANALYZE functional_dependencies;
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
  estimated | actual 
 -----------+--------
@@ -754,7 +758,8 @@ CREATE TABLE functional_dependencies_multi (
 	b INTEGER,
 	c INTEGER,
 	d INTEGER
-);
+)
+WITH (autovacuum_enabled = off);
 INSERT INTO functional_dependencies_multi (a, b, c, d)
     SELECT
          mod(i,7),
@@ -838,11 +843,12 @@ CREATE TABLE mcv_lists (
     filler3 DATE,
     c INT,
     d TEXT
-);
+)
+WITH (autovacuum_enabled = off);
 -- random data (no MCV list)
 INSERT INTO mcv_lists (a, b, c, filler1)
      SELECT mod(i,37), mod(i,41), mod(i,43), mod(i,47) FROM generate_series(1,5000) s(i);
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
  estimated | actual 
 -----------+--------
@@ -875,7 +881,7 @@ TRUNCATE mcv_lists;
 DROP STATISTICS mcv_lists_stats;
 INSERT INTO mcv_lists (a, b, c, filler1)
      SELECT mod(i,100), mod(i,50), mod(i,25), i FROM generate_series(1,5000) s(i);
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
  estimated | actual 
 -----------+--------
@@ -1175,7 +1181,7 @@ SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b =
          1 |     50
 (1 row)
 
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
  estimated | actual 
 -----------+--------
@@ -1192,7 +1198,7 @@ INSERT INTO mcv_lists (a, b, c, filler1)
          (CASE WHEN mod(i,25) = 1  THEN NULL ELSE mod(i,25) END),
          i
      FROM generate_series(1,5000) s(i);
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL');
  estimated | actual 
 -----------+--------
@@ -1259,7 +1265,7 @@ SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (0, 1) AN
 -- test pg_mcv_list_items with a very simple (single item) MCV list
 TRUNCATE mcv_lists;
 INSERT INTO mcv_lists (a, b, c) SELECT 1, 2, 3 FROM generate_series(1,1000) s(i);
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 SELECT m.*
   FROM pg_statistic_ext s, pg_statistic_ext_data d,
        pg_mcv_list_items(d.stxdmcv) m
@@ -1280,7 +1286,7 @@ INSERT INTO mcv_lists (a, b, c, d)
          (CASE WHEN mod(i,2) = 0 THEN NULL ELSE 0 END),
          (CASE WHEN mod(i,2) = 0 THEN NULL ELSE 'x' END)
      FROM generate_series(1,5000) s(i);
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE b = ''x'' OR d = ''x''');
  estimated | actual 
 -----------+--------
@@ -1337,7 +1343,8 @@ CREATE TABLE mcv_lists_uuid (
     a UUID,
     b UUID,
     c UUID
-);
+)
+WITH (autovacuum_enabled = off);
 INSERT INTO mcv_lists_uuid (a, b, c)
      SELECT
          md5(mod(i,100)::text)::uuid,
@@ -1378,7 +1385,8 @@ CREATE TABLE mcv_lists_arrays (
     a TEXT[],
     b NUMERIC[],
     c INT[]
-);
+)
+WITH (autovacuum_enabled = off);
 INSERT INTO mcv_lists_arrays (a, b, c)
      SELECT
          ARRAY[md5((i/100)::text), md5((i/100-1)::text), md5((i/100+1)::text)],
@@ -1393,12 +1401,13 @@ CREATE TABLE mcv_lists_bool (
     a BOOL,
     b BOOL,
     c BOOL
-);
+)
+WITH (autovacuum_enabled = off);
 INSERT INTO mcv_lists_bool (a, b, c)
      SELECT
          (mod(i,2) = 0), (mod(i,4) = 0), (mod(i,8) = 0)
      FROM generate_series(1,10000) s(i);
-VACUUM (ANALYZE) mcv_lists_bool;
+ANALYZE mcv_lists_bool;
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE a AND b AND c');
  estimated | actual 
 -----------+--------
@@ -1456,7 +1465,8 @@ CREATE TABLE mcv_lists_multi (
 	b INTEGER,
 	c INTEGER,
 	d INTEGER
-);
+)
+WITH (autovacuum_enabled = off);
 INSERT INTO mcv_lists_multi (a, b, c, d)
     SELECT
          mod(i,5),

src/test/regress/sql/stats_ext.sql

 -- Generic extended statistics support
 
--- We will be checking execution plans without/with statistics, so
--- let's make sure we get simple non-parallel plans. Also set the
--- work_mem low so that we can use small amounts of data.
+--
+-- Note: tables for which we check estimated row counts should be created
+-- with autovacuum_enabled = off, so that we don't have unstable results
+-- from auto-analyze happening when we didn't expect it.
+--
 
 -- check the number of estimated/actual rows in the top node
 create function check_estimated_rows(text) returns table (estimated int, actual int)
@@ -137,7 +139,8 @@ CREATE TABLE ndistinct (
     filler3 DATE,
     c INT,
     d INT
-);
+)
+WITH (autovacuum_enabled = off);
 
 -- over-estimates when using only per-column statistics
 INSERT INTO ndistinct (a, b, c, filler1)
@@ -191,7 +194,7 @@ INSERT INTO ndistinct (a, b, c, filler1)
             cash_words(mod(i,33)::int::money)
        FROM generate_series(1,5000) s(i);
 
-VACUUM (ANALYZE) ndistinct;
+ANALYZE ndistinct;
 
 SELECT s.stxkind, d.stxdndistinct
   FROM pg_statistic_ext s, pg_statistic_ext_data d
@@ -236,7 +239,8 @@ CREATE TABLE functional_dependencies (
     filler3 DATE,
     c INT,
     d TEXT
-);
+)
+WITH (autovacuum_enabled = off);
 
 CREATE INDEX fdeps_ab_idx ON functional_dependencies (a, b);
 CREATE INDEX fdeps_abc_idx ON functional_dependencies (a, b, c);
@@ -245,7 +249,7 @@ CREATE INDEX fdeps_abc_idx ON functional_dependencies (a, b, c);
 INSERT INTO functional_dependencies (a, b, c, filler1)
      SELECT mod(i, 23), mod(i, 29), mod(i, 31), i FROM generate_series(1,5000) s(i);
 
-VACUUM (ANALYZE) functional_dependencies;
+ANALYZE functional_dependencies;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
 
@@ -267,7 +271,7 @@ DROP STATISTICS func_deps_stat;
 INSERT INTO functional_dependencies (a, b, c, filler1)
      SELECT mod(i,100), mod(i,50), mod(i,25), i FROM generate_series(1,5000) s(i);
 
-VACUUM (ANALYZE) functional_dependencies;
+ANALYZE functional_dependencies;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
 
@@ -396,7 +400,7 @@ ALTER TABLE functional_dependencies ALTER COLUMN c TYPE numeric;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
 
-VACUUM (ANALYZE) functional_dependencies;
+ANALYZE functional_dependencies;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
 
@@ -406,7 +410,8 @@ CREATE TABLE functional_dependencies_multi (
 	b INTEGER,
 	c INTEGER,
 	d INTEGER
-);
+)
+WITH (autovacuum_enabled = off);
 
 INSERT INTO functional_dependencies_multi (a, b, c, d)
     SELECT
@@ -448,13 +453,14 @@ CREATE TABLE mcv_lists (
     filler3 DATE,
     c INT,
     d TEXT
-);
+)
+WITH (autovacuum_enabled = off);
 
 -- random data (no MCV list)
 INSERT INTO mcv_lists (a, b, c, filler1)
      SELECT mod(i,37), mod(i,41), mod(i,43), mod(i,47) FROM generate_series(1,5000) s(i);
 
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 
@@ -476,7 +482,7 @@ DROP STATISTICS mcv_lists_stats;
 INSERT INTO mcv_lists (a, b, c, filler1)
      SELECT mod(i,100), mod(i,50), mod(i,25), i FROM generate_series(1,5000) s(i);
 
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 
@@ -589,7 +595,7 @@ ALTER TABLE mcv_lists ALTER COLUMN c TYPE numeric;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 
@@ -605,7 +611,7 @@ INSERT INTO mcv_lists (a, b, c, filler1)
          i
      FROM generate_series(1,5000) s(i);
 
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL');
 
@@ -635,7 +641,8 @@ SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (0, 1) AN
 -- test pg_mcv_list_items with a very simple (single item) MCV list
 TRUNCATE mcv_lists;
 INSERT INTO mcv_lists (a, b, c) SELECT 1, 2, 3 FROM generate_series(1,1000) s(i);
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
+
 SELECT m.*
   FROM pg_statistic_ext s, pg_statistic_ext_data d,
        pg_mcv_list_items(d.stxdmcv) m
@@ -654,7 +661,7 @@ INSERT INTO mcv_lists (a, b, c, d)
          (CASE WHEN mod(i,2) = 0 THEN NULL ELSE 'x' END)
      FROM generate_series(1,5000) s(i);
 
-VACUUM (ANALYZE) mcv_lists;
+ANALYZE mcv_lists;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE b = ''x'' OR d = ''x''');
 
@@ -685,7 +692,8 @@ CREATE TABLE mcv_lists_uuid (
     a UUID,
     b UUID,
     c UUID
-);
+)
+WITH (autovacuum_enabled = off);
 
 INSERT INTO mcv_lists_uuid (a, b, c)
      SELECT
@@ -716,7 +724,8 @@ CREATE TABLE mcv_lists_arrays (
     a TEXT[],
     b NUMERIC[],
     c INT[]
-);
+)
+WITH (autovacuum_enabled = off);
 
 INSERT INTO mcv_lists_arrays (a, b, c)
      SELECT
@@ -735,14 +744,15 @@ CREATE TABLE mcv_lists_bool (
     a BOOL,
     b BOOL,
     c BOOL
-);
+)
+WITH (autovacuum_enabled = off);
 
 INSERT INTO mcv_lists_bool (a, b, c)
      SELECT
          (mod(i,2) = 0), (mod(i,4) = 0), (mod(i,8) = 0)
      FROM generate_series(1,10000) s(i);
 
-VACUUM (ANALYZE) mcv_lists_bool;
+ANALYZE mcv_lists_bool;
 
 SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE a AND b AND c');
 
@@ -771,7 +781,8 @@ CREATE TABLE mcv_lists_multi (
 	b INTEGER,
 	c INTEGER,
 	d INTEGER
-);
+)
+WITH (autovacuum_enabled = off);
 
 INSERT INTO mcv_lists_multi (a, b, c, d)
     SELECT