just_pg_statistic_set_difference_tests.diff

diff --git a/src/test/regress/sql/stats_import.sql b/src/test/regress/sql/stats_import.sql
index 61535a971dc..a4a16b50a50 100644
--- a/src/test/regress/sql/stats_import.sql
+++ b/src/test/regress/sql/stats_import.sql
@@ -884,113 +884,60 @@ AND c.relname IN ('test', 'test_clone', 'is_odd', 'is_odd_clone')
 GROUP BY c.relname
 ORDER BY c.relname;
 
--- check test minus test_clone
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'test' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.test'::regclass
-EXCEPT
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'test' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.test_clone'::regclass;
+-- Test to detect any new columns added to pg_statistic, which may in turn
+-- need to be added to pg_statistic_flat()
+SELECT COUNT(*)
+FROM pg_attribute
+WHERE attrelid = 'pg_catalog.pg_statistic'::regclass;
+-- Create a view that is used purely for the type
+CREATE VIEW stats_import.pgs_t AS
+  SELECT
+      a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
+      s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
+      s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
+      s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
+      s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
+      s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
+      s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
+      s.stavalues5::text AS sv5
+  FROM pg_statistic s
+  JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
+  WHERE FALSE;
+-- Function to get only the set-diff comparable parts of pg_statistic
+CREATE FUNCTION stats_import.pg_statistic_flat(p_relname text)
+RETURNS SETOF stats_import.pgs_t
+BEGIN ATOMIC
+  SELECT a.attname, s.stainherit, s.stanullfrac, s.stawidth,
+      s.stadistinct, s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
+      s.staop1, s.staop2, s.staop3, s.staop4, s.staop5, s.stacoll1, s.stacoll2,
+      s.stacoll3, s.stacoll4, s.stacoll5, s.stanumbers1, s.stanumbers2,
+      s.stanumbers3, s.stanumbers4, s.stanumbers5, s.stavalues1::text,
+      s.stavalues2::text, s.stavalues3::text,
+      s.stavalues4::text, s.stavalues5::text
+  FROM pg_statistic s
+  JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
+  JOIN pg_class c ON c.oid = a.attrelid
+  WHERE c.relnamespace = 'stats_import'::regnamespace
+  AND c.relname = p_relname;
+END;
+-- pg_statistic set diff function
+CREATE FUNCTION stats_import.pg_statistic_set_difference(a text, b text)
+RETURNS TABLE (relname text, stats stats_import.pgs_t)
+BEGIN ATOMIC
+  WITH aset AS (SELECT * FROM stats_import.pg_statistic_flat(a)),
+       bset AS (SELECT * FROM stats_import.pg_statistic_flat(b))
+  SELECT a AS relname, a_minus_b::stats_import.pgs_t
+  FROM (TABLE aset EXCEPT TABLE bset) AS a_minus_b
+  UNION ALL
+  SELECT b AS relname, b_minus_a::stats_import.pgs_t
+  FROM (TABLE bset EXCEPT TABLE aset) AS b_minus_a;
+END;
 
--- check test_clone minus test
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'test_clone' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.test_clone'::regclass
-EXCEPT
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'test_clone' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.test'::regclass;
+SELECT relname, (stats).*
+FROM stats_import.pg_statistic_set_difference('test', 'test_clone') \gx
 
--- check is_odd minus is_odd_clone
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'is_odd' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.is_odd'::regclass
-EXCEPT
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'is_odd' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.is_odd_clone'::regclass;
-
--- check is_odd_clone minus is_odd
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'is_odd_clone' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.is_odd_clone'::regclass
-EXCEPT
-SELECT
-    a.attname, s.stainherit, s.stanullfrac, s.stawidth, s.stadistinct,
-    s.stakind1, s.stakind2, s.stakind3, s.stakind4, s.stakind5,
-    s.staop1, s.staop2, s.staop3, s.staop4, s.staop5,
-    s.stacoll1, s.stacoll2, s.stacoll3, s.stacoll4, s.stacoll5,
-    s.stanumbers1, s.stanumbers2, s.stanumbers3, s.stanumbers4, s.stanumbers5,
-    s.stavalues1::text AS sv1, s.stavalues2::text AS sv2,
-    s.stavalues3::text AS sv3, s.stavalues4::text AS sv4,
-    s.stavalues5::text AS sv5, 'is_odd_clone' AS direction
-FROM pg_statistic s
-JOIN pg_attribute a ON a.attrelid = s.starelid AND a.attnum = s.staattnum
-WHERE s.starelid = 'stats_import.is_odd'::regclass;
+SELECT relname, (stats).*
+FROM stats_import.pg_statistic_set_difference('is_odd', 'is_odd_clone') \gx
 
 -- attribute stats exist before a clear, but not after
 SELECT COUNT(*)