Add an ORDER BY to nail down the expected row order from a query that's

been shown to be sensitive to concurrent autovacuum.  Per Alvaro.

src/test/regress/expected/cluster.out

@@ -249,11 +249,12 @@ SELECT a,b,c,substring(d for 30), length(d) from clstr_tst;
 INSERT INTO clstr_tst (b, c) VALUES (1111, 'this should fail');
 ERROR:  insert or update on table "clstr_tst" violates foreign key constraint "clstr_tst_con"
 DETAIL:  Key (b)=(1111) is not present in table "clstr_tst_s".
-SELECT conname FROM pg_constraint WHERE conrelid = 'clstr_tst'::regclass;
+SELECT conname FROM pg_constraint WHERE conrelid = 'clstr_tst'::regclass
+ORDER BY 1;
     conname     
 ----------------
- clstr_tst_pkey
  clstr_tst_con
+ clstr_tst_pkey
 (2 rows)
 
 SELECT relname, relkind,

src/test/regress/sql/cluster.sql

@@ -73,7 +73,8 @@ SELECT a,b,c,substring(d for 30), length(d) from clstr_tst;
 -- Verify that foreign key link still works
 INSERT INTO clstr_tst (b, c) VALUES (1111, 'this should fail');
 
-SELECT conname FROM pg_constraint WHERE conrelid = 'clstr_tst'::regclass;
+SELECT conname FROM pg_constraint WHERE conrelid = 'clstr_tst'::regclass
+ORDER BY 1;
 
 
 SELECT relname, relkind,