Refactor tests for catalog diff comparisons in stats_import.sql

The tests of stats_import.sql include a set of queries to do
differential checks of the three statistics catalog relations, based on
the comparison of a source relation and a target relation, used for the
copy of the stats data with the restore functions:
- pg_statistic
- pg_stats_ext
- pg_stats_ext_exprs

This commit refactors the tests to reduce the bloat of such differential
queries, by creating a set of objects that make the differential queries
smaller:
- View for a base relation type.
- First function to retrieve stats data, that returns a type based on
the view previously created.
- Second function that checks the difference, based on two calls of the
first function.

This change leads to a nice reduction of stats_import.sql, with a larger
effect on the output file.

While on it, this adds some sanity checks for the three catalogs, to
warn developers that the stats import facilities may need to be updated
if any of the three catalogs change.  These are rare in practice, see
918eee0c497c as one example.  Another stylistic change is the use of the
extended output format for the differential queries, so as we avoid long
lines of output if a diff is caught.

Author: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://postgr.es/m/CADkLM=eEhxJpSUP+eC=eMGZZsVOpnfKDvVkuCbsFg9CajYwDsA@mail.gmail.com

diff --git a/src/test/regress/expected/stats_import.out b/src/test/regress/expected/stats_import.out
index 00a46353041c14b0827aefbb0ebb6a51e9185372..c7adb783da2117b8f86aa7b1e4651a70016606a6 100644 (file)
--- a/src/test/regress/expected/stats_import.out
+++ b/src/test/regress/expected/stats_import.out
@@ -1,4 +1,158 @@
 CREATE SCHEMA stats_import;
+--
+-- Setup functions for set-difference convenience functions
+--
+-- Test to detect any new columns added to pg_statistic.  If any columns
+-- are added, we may need to update pg_statistic_flat() and the facilities
+-- we are testing.
+SELECT COUNT(*) FROM pg_attribute
+  WHERE attrelid = 'pg_catalog.pg_statistic'::regclass AND
+    attnum > 0;
+ count 
+-------
+    31
+(1 row)
+
+-- Create a view that is used purely for the type based on pg_statistic.
+CREATE VIEW stats_import.pg_statistic_flat_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 retrieve data used for diff comparisons between two
+-- relations based on the contents of pg_statistic.
+CREATE FUNCTION stats_import.pg_statistic_flat(p_relname text)
+RETURNS SETOF stats_import.pg_statistic_flat_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;
+-- Comparison function for pg_statistic.  The two relations defined by
+-- the function caller are compared.
+CREATE FUNCTION stats_import.pg_statistic_get_difference(a text, b text)
+RETURNS TABLE (relname text, stats stats_import.pg_statistic_flat_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.pg_statistic_flat_t
+  FROM (TABLE aset EXCEPT TABLE bset) AS a_minus_b
+  UNION ALL
+  SELECT b AS relname, b_minus_a::stats_import.pg_statistic_flat_t
+  FROM (TABLE bset EXCEPT TABLE aset) AS b_minus_a;
+END;
+-- Test to detect any new columns added to pg_stats_ext.  If any columns
+-- are added, we may need to update pg_stats_ext_flat() and the facilities
+-- we are testing.
+SELECT COUNT(*) FROM pg_attribute
+  WHERE attrelid = 'pg_catalog.pg_stats_ext'::regclass AND
+    attnum > 0;
+ count 
+-------
+    15
+(1 row)
+
+-- Create a view that is used purely for the type based on pg_stats_ext.
+CREATE VIEW stats_import.pg_stats_ext_flat_t AS
+  SELECT inherited, n_distinct, dependencies, most_common_vals,
+         most_common_freqs, most_common_base_freqs
+  FROM pg_stats_ext
+  WHERE FALSE;
+-- Function to retrieve data used for diff comparisons between two
+-- relations based on the contents of pg_stats_ext.
+CREATE FUNCTION stats_import.pg_stats_ext_flat(p_statname text)
+RETURNS SETOF stats_import.pg_stats_ext_flat_t
+BEGIN ATOMIC
+  SELECT inherited, n_distinct, dependencies, most_common_vals,
+         most_common_freqs, most_common_base_freqs
+  FROM pg_stats_ext
+  WHERE statistics_schemaname = 'stats_import'
+  AND statistics_name = p_statname;
+END;
+-- Comparison function for pg_stats_ext.  The two relations defined by
+-- the function caller are compared.
+CREATE FUNCTION stats_import.pg_stats_ext_get_difference(a text, b text)
+RETURNS TABLE (statname text, stats stats_import.pg_stats_ext_flat_t)
+BEGIN ATOMIC
+  WITH aset AS (SELECT * FROM stats_import.pg_stats_ext_flat(a)),
+       bset AS (SELECT * FROM stats_import.pg_stats_ext_flat(b))
+  SELECT a AS relname, a_minus_b::stats_import.pg_stats_ext_flat_t
+  FROM (TABLE aset EXCEPT TABLE bset) AS a_minus_b
+  UNION ALL
+  SELECT b AS relname, b_minus_a::stats_import.pg_stats_ext_flat_t
+  FROM (TABLE bset EXCEPT TABLE aset) AS b_minus_a;
+END;
+-- Test to detect any new columns added to pg_stats_ext_exprs.  If any columns
+-- are added, we may need to update pg_stats_ext_exprs_flat() and the facilities
+-- we are testing.
+SELECT COUNT(*) FROM pg_attribute
+  WHERE attrelid = 'pg_catalog.pg_stats_ext_exprs'::regclass AND
+    attnum > 0;
+ count 
+-------
+    20
+(1 row)
+
+-- Create a view that is used purely for the type based on pg_stats_ext_exprs.
+CREATE VIEW stats_import.pg_stats_ext_exprs_flat_t AS
+  SELECT inherited, null_frac, avg_width, n_distinct,
+       most_common_vals::text AS most_common_vals,
+       most_common_freqs, histogram_bounds::text AS histogram_bounds,
+       correlation, most_common_elems::text AS most_common_elems,
+       most_common_elem_freqs, elem_count_histogram,
+       range_length_histogram::text AS range_length_histogram,
+       range_empty_frac, range_bounds_histogram::text AS range_bounds_histogram
+  FROM pg_stats_ext_exprs AS n
+  WHERE FALSE;
+-- Function to retrieve data used for diff comparisons between two
+-- relations based on the contents of pg_stats_ext_exprs.
+CREATE FUNCTION stats_import.pg_stats_ext_exprs_flat(p_statname text)
+RETURNS SETOF stats_import.pg_stats_ext_exprs_flat_t
+BEGIN ATOMIC
+  SELECT inherited, null_frac, avg_width, n_distinct,
+       most_common_vals::text AS most_common_vals,
+       most_common_freqs, histogram_bounds::text AS histogram_bounds,
+       correlation, most_common_elems::text AS most_common_elems,
+       most_common_elem_freqs, elem_count_histogram,
+       range_length_histogram::text AS range_length_histogram,
+       range_empty_frac, range_bounds_histogram::text AS range_bounds_histogram
+  FROM pg_stats_ext_exprs AS n
+  WHERE n.statistics_schemaname = 'stats_import' AND
+    n.statistics_name = p_statname;
+END;
+-- Comparison function for pg_stats_ext_exprs.  The two relations defined by
+-- the function caller are compared.
+CREATE FUNCTION stats_import.pg_stats_ext_exprs_get_difference(a text, b text)
+RETURNS TABLE (statname text, stats stats_import.pg_stats_ext_exprs_flat_t)
+BEGIN ATOMIC
+  WITH aset AS (SELECT * FROM stats_import.pg_stats_ext_exprs_flat(a)),
+       bset AS (SELECT * FROM stats_import.pg_stats_ext_exprs_flat(b))
+  SELECT a AS relname, a_minus_b::stats_import.pg_stats_ext_exprs_flat_t
+  FROM (TABLE aset EXCEPT TABLE bset) AS a_minus_b
+  UNION ALL
+  SELECT b AS relname, b_minus_a::stats_import.pg_stats_ext_exprs_flat_t
+  FROM (TABLE bset EXCEPT TABLE aset) AS b_minus_a;
+END;
+--
+-- Schema setup.
+--
 CREATE TYPE stats_import.complex_type AS (
     a integer,
     b real,
@@ -1220,124 +1374,14 @@ ORDER BY c.relname;
  test_clone   |         5
 (4 rows)
 
--- 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;
- attname | stainherit | stanullfrac | stawidth | stadistinct | stakind1 | stakind2 | stakind3 | stakind4 | stakind5 | staop1 | staop2 | staop3 | staop4 | staop5 | stacoll1 | stacoll2 | stacoll3 | stacoll4 | stacoll5 | stanumbers1 | stanumbers2 | stanumbers3 | stanumbers4 | stanumbers5 | sv1 | sv2 | sv3 | sv4 | sv5 | direction 
----------+------------+-------------+----------+-------------+----------+----------+----------+----------+----------+--------+--------+--------+--------+--------+----------+----------+----------+----------+----------+-------------+-------------+-------------+-------------+-------------+-----+-----+-----+-----+-----+-----------
-(0 rows)
-
--- 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;
- attname | stainherit | stanullfrac | stawidth | stadistinct | stakind1 | stakind2 | stakind3 | stakind4 | stakind5 | staop1 | staop2 | staop3 | staop4 | staop5 | stacoll1 | stacoll2 | stacoll3 | stacoll4 | stacoll5 | stanumbers1 | stanumbers2 | stanumbers3 | stanumbers4 | stanumbers5 | sv1 | sv2 | sv3 | sv4 | sv5 | direction 
----------+------------+-------------+----------+-------------+----------+----------+----------+----------+----------+--------+--------+--------+--------+--------+----------+----------+----------+----------+----------+-------------+-------------+-------------+-------------+-------------+-----+-----+-----+-----+-----+-----------
-(0 rows)
-
--- 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;
- attname | stainherit | stanullfrac | stawidth | stadistinct | stakind1 | stakind2 | stakind3 | stakind4 | stakind5 | staop1 | staop2 | staop3 | staop4 | staop5 | stacoll1 | stacoll2 | stacoll3 | stacoll4 | stacoll5 | stanumbers1 | stanumbers2 | stanumbers3 | stanumbers4 | stanumbers5 | sv1 | sv2 | sv3 | sv4 | sv5 | direction 
----------+------------+-------------+----------+-------------+----------+----------+----------+----------+----------+--------+--------+--------+--------+--------+----------+----------+----------+----------+----------+-------------+-------------+-------------+-------------+-------------+-----+-----+-----+-----+-----+-----------
+SELECT relname, (stats).*
+FROM stats_import.pg_statistic_get_difference('test', 'test_clone')
+\gx
 (0 rows)
 
--- 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;
- attname | stainherit | stanullfrac | stawidth | stadistinct | stakind1 | stakind2 | stakind3 | stakind4 | stakind5 | staop1 | staop2 | staop3 | staop4 | staop5 | stacoll1 | stacoll2 | stacoll3 | stacoll4 | stacoll5 | stanumbers1 | stanumbers2 | stanumbers3 | stanumbers4 | stanumbers5 | sv1 | sv2 | sv3 | sv4 | sv5 | direction 
----------+------------+-------------+----------+-------------+----------+----------+----------+----------+----------+--------+--------+--------+--------+--------+----------+----------+----------+----------+----------+-------------+-------------+-------------+-------------+-------------+-----+-----+-----+-----+-----+-----------
+SELECT relname, (stats).*
+FROM stats_import.pg_statistic_get_difference('is_odd', 'is_odd_clone')
+\gx
 (0 rows)
 
 -- attribute stats exist before a clear, but not after
@@ -3169,108 +3213,14 @@ AND e.statistics_name = 'test_stat';
  test_stat       | t
 (1 row)
 
--- Set difference old MINUS new.
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat'
-EXCEPT
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone';
- inherited | n_distinct | dependencies | most_common_vals | most_common_freqs | most_common_base_freqs 
------------+------------+--------------+------------------+-------------------+------------------------
-(0 rows)
-
--- Set difference new MINUS old.
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat';
- inherited | n_distinct | dependencies | most_common_vals | most_common_freqs | most_common_base_freqs 
------------+------------+--------------+------------------+-------------------+------------------------
-(0 rows)
-
--- Set difference for exprs: old MINUS new.
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat'
-EXCEPT
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone';
- inherited | null_frac | avg_width | n_distinct | most_common_vals | most_common_freqs | histogram_bounds | correlation | most_common_elems | most_common_elem_freqs | elem_count_histogram | range_length_histogram | range_empty_frac | range_bounds_histogram 
------------+-----------+-----------+------------+------------------+-------------------+------------------+-------------+-------------------+------------------------+----------------------+------------------------+------------------+------------------------
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_get_difference('test_stat', 'test_stat_clone')
+\gx
 (0 rows)
 
--- Set difference for exprs: new MINUS old.
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat';
- inherited | null_frac | avg_width | n_distinct | most_common_vals | most_common_freqs | histogram_bounds | correlation | most_common_elems | most_common_elem_freqs | elem_count_histogram | range_length_histogram | range_empty_frac | range_bounds_histogram 
------------+-----------+-----------+------------+------------------+-------------------+------------------+-------------+-------------------+------------------------+----------------------+------------------------+------------------+------------------------
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_exprs_get_difference('test_stat', 'test_stat_clone')
+\gx
 (0 rows)
 
 ANALYZE stats_import.test_mr;
@@ -3316,108 +3266,14 @@ AND e.statistics_name = 'test_mr_stat';
  test_mr_stat    | t
 (1 row)
 
--- Set difference old MINUS new.
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat'
-EXCEPT
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone';
- inherited | n_distinct | dependencies | most_common_vals | most_common_freqs | most_common_base_freqs 
------------+------------+--------------+------------------+-------------------+------------------------
-(0 rows)
-
--- Set difference new MINUS old.
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat';
- inherited | n_distinct | dependencies | most_common_vals | most_common_freqs | most_common_base_freqs 
------------+------------+--------------+------------------+-------------------+------------------------
-(0 rows)
-
--- Set difference for exprs: old MINUS new.
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat'
-EXCEPT
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone';
- inherited | null_frac | avg_width | n_distinct | most_common_vals | most_common_freqs | histogram_bounds | correlation | most_common_elems | most_common_elem_freqs | elem_count_histogram | range_length_histogram | range_empty_frac | range_bounds_histogram 
------------+-----------+-----------+------------+------------------+-------------------+------------------+-------------+-------------------+------------------------+----------------------+------------------------+------------------+------------------------
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_get_difference('test_mr_stat', 'test_mr_stat_clone')
+\gx
 (0 rows)
 
--- Set difference for exprs: new MINUS old.
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat';
- inherited | null_frac | avg_width | n_distinct | most_common_vals | most_common_freqs | histogram_bounds | correlation | most_common_elems | most_common_elem_freqs | elem_count_histogram | range_length_histogram | range_empty_frac | range_bounds_histogram 
------------+-----------+-----------+------------+------------------+-------------------+------------------+-------------+-------------------+------------------------+----------------------+------------------------+------------------+------------------------
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_exprs_get_difference('test_mr_stat', 'test_mr_stat_clone')
+\gx
 (0 rows)
 
 -- range_length_histogram, range_empty_frac, and range_bounds_histogram
@@ -3506,8 +3362,17 @@ SELECT COUNT(*) FROM stats_import.test_range_expr_null
 (1 row)
 
 DROP SCHEMA stats_import CASCADE;
-NOTICE:  drop cascades to 9 other objects
-DETAIL:  drop cascades to type stats_import.complex_type
+NOTICE:  drop cascades to 18 other objects
+DETAIL:  drop cascades to view stats_import.pg_statistic_flat_t
+drop cascades to function stats_import.pg_statistic_flat(text)
+drop cascades to function stats_import.pg_statistic_get_difference(text,text)
+drop cascades to view stats_import.pg_stats_ext_flat_t
+drop cascades to function stats_import.pg_stats_ext_flat(text)
+drop cascades to function stats_import.pg_stats_ext_get_difference(text,text)
+drop cascades to view stats_import.pg_stats_ext_exprs_flat_t
+drop cascades to function stats_import.pg_stats_ext_exprs_flat(text)
+drop cascades to function stats_import.pg_stats_ext_exprs_get_difference(text,text)
+drop cascades to type stats_import.complex_type
 drop cascades to table stats_import.test
 drop cascades to table stats_import.test_mr
 drop cascades to table stats_import.part_parent

diff --git a/src/test/regress/sql/stats_import.sql b/src/test/regress/sql/stats_import.sql
index 57363ab374843f1bf7396d07a251806ff586c72d..0518bbf6f425669aea911933af03db1c762b25c5 100644 (file)
--- a/src/test/regress/sql/stats_import.sql
+++ b/src/test/regress/sql/stats_import.sql
@@ -1,5 +1,157 @@
 CREATE SCHEMA stats_import;
 
+--
+-- Setup functions for set-difference convenience functions
+--
+
+-- Test to detect any new columns added to pg_statistic.  If any columns
+-- are added, we may need to update pg_statistic_flat() and the facilities
+-- we are testing.
+SELECT COUNT(*) FROM pg_attribute
+  WHERE attrelid = 'pg_catalog.pg_statistic'::regclass AND
+    attnum > 0;
+
+-- Create a view that is used purely for the type based on pg_statistic.
+CREATE VIEW stats_import.pg_statistic_flat_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 retrieve data used for diff comparisons between two
+-- relations based on the contents of pg_statistic.
+CREATE FUNCTION stats_import.pg_statistic_flat(p_relname text)
+RETURNS SETOF stats_import.pg_statistic_flat_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;
+
+-- Comparison function for pg_statistic.  The two relations defined by
+-- the function caller are compared.
+CREATE FUNCTION stats_import.pg_statistic_get_difference(a text, b text)
+RETURNS TABLE (relname text, stats stats_import.pg_statistic_flat_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.pg_statistic_flat_t
+  FROM (TABLE aset EXCEPT TABLE bset) AS a_minus_b
+  UNION ALL
+  SELECT b AS relname, b_minus_a::stats_import.pg_statistic_flat_t
+  FROM (TABLE bset EXCEPT TABLE aset) AS b_minus_a;
+END;
+
+-- Test to detect any new columns added to pg_stats_ext.  If any columns
+-- are added, we may need to update pg_stats_ext_flat() and the facilities
+-- we are testing.
+SELECT COUNT(*) FROM pg_attribute
+  WHERE attrelid = 'pg_catalog.pg_stats_ext'::regclass AND
+    attnum > 0;
+
+-- Create a view that is used purely for the type based on pg_stats_ext.
+CREATE VIEW stats_import.pg_stats_ext_flat_t AS
+  SELECT inherited, n_distinct, dependencies, most_common_vals,
+         most_common_freqs, most_common_base_freqs
+  FROM pg_stats_ext
+  WHERE FALSE;
+
+-- Function to retrieve data used for diff comparisons between two
+-- relations based on the contents of pg_stats_ext.
+CREATE FUNCTION stats_import.pg_stats_ext_flat(p_statname text)
+RETURNS SETOF stats_import.pg_stats_ext_flat_t
+BEGIN ATOMIC
+  SELECT inherited, n_distinct, dependencies, most_common_vals,
+         most_common_freqs, most_common_base_freqs
+  FROM pg_stats_ext
+  WHERE statistics_schemaname = 'stats_import'
+  AND statistics_name = p_statname;
+END;
+
+-- Comparison function for pg_stats_ext.  The two relations defined by
+-- the function caller are compared.
+CREATE FUNCTION stats_import.pg_stats_ext_get_difference(a text, b text)
+RETURNS TABLE (statname text, stats stats_import.pg_stats_ext_flat_t)
+BEGIN ATOMIC
+  WITH aset AS (SELECT * FROM stats_import.pg_stats_ext_flat(a)),
+       bset AS (SELECT * FROM stats_import.pg_stats_ext_flat(b))
+  SELECT a AS relname, a_minus_b::stats_import.pg_stats_ext_flat_t
+  FROM (TABLE aset EXCEPT TABLE bset) AS a_minus_b
+  UNION ALL
+  SELECT b AS relname, b_minus_a::stats_import.pg_stats_ext_flat_t
+  FROM (TABLE bset EXCEPT TABLE aset) AS b_minus_a;
+END;
+
+-- Test to detect any new columns added to pg_stats_ext_exprs.  If any columns
+-- are added, we may need to update pg_stats_ext_exprs_flat() and the facilities
+-- we are testing.
+SELECT COUNT(*) FROM pg_attribute
+  WHERE attrelid = 'pg_catalog.pg_stats_ext_exprs'::regclass AND
+    attnum > 0;
+
+-- Create a view that is used purely for the type based on pg_stats_ext_exprs.
+CREATE VIEW stats_import.pg_stats_ext_exprs_flat_t AS
+  SELECT inherited, null_frac, avg_width, n_distinct,
+       most_common_vals::text AS most_common_vals,
+       most_common_freqs, histogram_bounds::text AS histogram_bounds,
+       correlation, most_common_elems::text AS most_common_elems,
+       most_common_elem_freqs, elem_count_histogram,
+       range_length_histogram::text AS range_length_histogram,
+       range_empty_frac, range_bounds_histogram::text AS range_bounds_histogram
+  FROM pg_stats_ext_exprs AS n
+  WHERE FALSE;
+
+-- Function to retrieve data used for diff comparisons between two
+-- relations based on the contents of pg_stats_ext_exprs.
+CREATE FUNCTION stats_import.pg_stats_ext_exprs_flat(p_statname text)
+RETURNS SETOF stats_import.pg_stats_ext_exprs_flat_t
+BEGIN ATOMIC
+  SELECT inherited, null_frac, avg_width, n_distinct,
+       most_common_vals::text AS most_common_vals,
+       most_common_freqs, histogram_bounds::text AS histogram_bounds,
+       correlation, most_common_elems::text AS most_common_elems,
+       most_common_elem_freqs, elem_count_histogram,
+       range_length_histogram::text AS range_length_histogram,
+       range_empty_frac, range_bounds_histogram::text AS range_bounds_histogram
+  FROM pg_stats_ext_exprs AS n
+  WHERE n.statistics_schemaname = 'stats_import' AND
+    n.statistics_name = p_statname;
+END;
+
+-- Comparison function for pg_stats_ext_exprs.  The two relations defined by
+-- the function caller are compared.
+CREATE FUNCTION stats_import.pg_stats_ext_exprs_get_difference(a text, b text)
+RETURNS TABLE (statname text, stats stats_import.pg_stats_ext_exprs_flat_t)
+BEGIN ATOMIC
+  WITH aset AS (SELECT * FROM stats_import.pg_stats_ext_exprs_flat(a)),
+       bset AS (SELECT * FROM stats_import.pg_stats_ext_exprs_flat(b))
+  SELECT a AS relname, a_minus_b::stats_import.pg_stats_ext_exprs_flat_t
+  FROM (TABLE aset EXCEPT TABLE bset) AS a_minus_b
+  UNION ALL
+  SELECT b AS relname, b_minus_a::stats_import.pg_stats_ext_exprs_flat_t
+  FROM (TABLE bset EXCEPT TABLE aset) AS b_minus_a;
+END;
+
+--
+-- Schema setup.
+--
 CREATE TYPE stats_import.complex_type AS (
     a integer,
     b real,
@@ -884,113 +1036,13 @@ 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;
-
--- 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;
-
--- 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_get_difference('test', 'test_clone')
+\gx
+
+SELECT relname, (stats).*
+FROM stats_import.pg_statistic_get_difference('is_odd', 'is_odd_clone')
+\gx
 
 -- attribute stats exist before a clear, but not after
 SELECT COUNT(*)
@@ -2171,96 +2223,14 @@ CROSS JOIN LATERAL (
 WHERE e.statistics_schemaname = 'stats_import'
 AND e.statistics_name = 'test_stat';
 
--- Set difference old MINUS new.
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat'
-EXCEPT
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone';
--- Set difference new MINUS old.
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat';
-
--- Set difference for exprs: old MINUS new.
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat'
-EXCEPT
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone';
-
--- Set difference for exprs: new MINUS old.
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_stat';
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_get_difference('test_stat', 'test_stat_clone')
+\gx
+
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_exprs_get_difference('test_stat', 'test_stat_clone')
+\gx
+
 
 ANALYZE stats_import.test_mr;
 
@@ -2302,96 +2272,13 @@ CROSS JOIN LATERAL (
 WHERE e.statistics_schemaname = 'stats_import'
 AND e.statistics_name = 'test_mr_stat';
 
--- Set difference old MINUS new.
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat'
-EXCEPT
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone';
--- Set difference new MINUS old.
-SELECT n.inherited,
-       n.n_distinct, n.dependencies, n.most_common_vals,
-       n.most_common_freqs, n.most_common_base_freqs
-  FROM pg_stats_ext AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.n_distinct, o.dependencies, o.most_common_vals,
-       o.most_common_freqs, o.most_common_base_freqs
-  FROM pg_stats_ext AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat';
-
--- Set difference for exprs: old MINUS new.
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat'
-EXCEPT
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone';
-
--- Set difference for exprs: new MINUS old.
-SELECT n.inherited,
-       n.null_frac, n.avg_width, n.n_distinct,
-       n.most_common_vals::text AS most_common_vals,
-       n.most_common_freqs,
-       n.histogram_bounds::text AS histogram_bounds,
-       n.correlation,
-       n.most_common_elems::text AS most_common_elems,
-       n.most_common_elem_freqs, n.elem_count_histogram,
-       n.range_length_histogram::text AS range_length_histogram,
-       n.range_empty_frac,
-       n.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS n
-  WHERE n.statistics_schemaname = 'stats_import' AND
-    n.statistics_name = 'test_mr_stat_clone'
-EXCEPT
-SELECT o.inherited,
-       o.null_frac, o.avg_width, o.n_distinct,
-       o.most_common_vals::text AS most_common_vals,
-       o.most_common_freqs,
-       o.histogram_bounds::text AS histogram_bounds,
-       o.correlation,
-       o.most_common_elems::text AS most_common_elems,
-       o.most_common_elem_freqs, o.elem_count_histogram,
-       o.range_length_histogram::text AS range_length_histogram,
-       o.range_empty_frac,
-       o.range_bounds_histogram::text AS range_bounds_histogram
-  FROM pg_stats_ext_exprs AS o
-  WHERE o.statistics_schemaname = 'stats_import' AND
-    o.statistics_name = 'test_mr_stat';
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_get_difference('test_mr_stat', 'test_mr_stat_clone')
+\gx
+
+SELECT statname, (stats).*
+FROM stats_import.pg_stats_ext_exprs_get_difference('test_mr_stat', 'test_mr_stat_clone')
+\gx
 
 -- range_length_histogram, range_empty_frac, and range_bounds_histogram
 -- have been added to pg_stats_ext_exprs in PostgreSQL 19.  When dumping