-- Generic extended statistics support
--
-- 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
$$
declare
    ln text;
    tmp text[];
    first_row bool := true;
begin
    for ln in
        execute format('explain analyze %s', $1)
    loop
        if first_row then
            first_row := false;
            tmp := regexp_match(ln, 'rows=(\d*) .* rows=(\d*)');
            return query select tmp[1]::int, tmp[2]::int;
        end if;
    end loop;
end;
$$;
-- Verify failures
CREATE STATISTICS tst;
ERROR:  syntax error at or near ";"
LINE 1: CREATE STATISTICS tst;
                             ^
CREATE STATISTICS tst ON a, b;
ERROR:  syntax error at or near ";"
LINE 1: CREATE STATISTICS tst ON a, b;
                                     ^
CREATE STATISTICS tst FROM sometab;
ERROR:  syntax error at or near "FROM"
LINE 1: CREATE STATISTICS tst FROM sometab;
                              ^
CREATE STATISTICS tst ON a, b FROM nonexistent;
ERROR:  relation "nonexistent" does not exist
CREATE STATISTICS tst ON a, b FROM pg_class;
ERROR:  column "a" does not exist
CREATE STATISTICS tst ON relname, relname, relnatts FROM pg_class;
ERROR:  duplicate column name in statistics definition
CREATE STATISTICS tst ON relnatts + relpages FROM pg_class;
ERROR:  only simple column references are allowed in CREATE STATISTICS
CREATE STATISTICS tst ON (relpages, reltuples) FROM pg_class;
ERROR:  only simple column references are allowed in CREATE STATISTICS
CREATE STATISTICS tst (unrecognized) ON relname, relnatts FROM pg_class;
ERROR:  unrecognized statistics kind "unrecognized"
-- Ensure stats are dropped sanely, and test IF NOT EXISTS while at it
CREATE TABLE ab1 (a INTEGER, b INTEGER, c INTEGER);
CREATE STATISTICS IF NOT EXISTS ab1_a_b_stats ON a, b FROM ab1;
CREATE STATISTICS IF NOT EXISTS ab1_a_b_stats ON a, b FROM ab1;
NOTICE:  statistics object "ab1_a_b_stats" already exists, skipping
DROP STATISTICS ab1_a_b_stats;
CREATE SCHEMA regress_schema_2;
CREATE STATISTICS regress_schema_2.ab1_a_b_stats ON a, b FROM ab1;
-- Let's also verify the pg_get_statisticsobjdef output looks sane.
SELECT pg_get_statisticsobjdef(oid) FROM pg_statistic_ext WHERE stxname = 'ab1_a_b_stats';
                      pg_get_statisticsobjdef                      
-------------------------------------------------------------------
 CREATE STATISTICS regress_schema_2.ab1_a_b_stats ON a, b FROM ab1
(1 row)

DROP STATISTICS regress_schema_2.ab1_a_b_stats;
-- Ensure statistics are dropped when columns are
CREATE STATISTICS ab1_b_c_stats ON b, c FROM ab1;
CREATE STATISTICS ab1_a_b_c_stats ON a, b, c FROM ab1;
CREATE STATISTICS ab1_b_a_stats ON b, a FROM ab1;
ALTER TABLE ab1 DROP COLUMN a;
\d ab1
                Table "public.ab1"
 Column |  Type   | Collation | Nullable | Default 
--------+---------+-----------+----------+---------
 b      | integer |           |          | 
 c      | integer |           |          | 
Statistics objects:
    "public"."ab1_b_c_stats" (ndistinct, dependencies, mcv) ON b, c FROM ab1

-- Ensure statistics are dropped when table is
SELECT stxname FROM pg_statistic_ext WHERE stxname LIKE 'ab1%';
    stxname    
---------------
 ab1_b_c_stats
(1 row)

DROP TABLE ab1;
SELECT stxname FROM pg_statistic_ext WHERE stxname LIKE 'ab1%';
 stxname 
---------
(0 rows)

-- Ensure things work sanely with SET STATISTICS 0
CREATE TABLE ab1 (a INTEGER, b INTEGER);
ALTER TABLE ab1 ALTER a SET STATISTICS 0;
INSERT INTO ab1 SELECT a, a%23 FROM generate_series(1, 1000) a;
CREATE STATISTICS ab1_a_b_stats ON a, b FROM ab1;
ANALYZE ab1;
WARNING:  statistics object "public.ab1_a_b_stats" could not be computed for relation "public.ab1"
ALTER TABLE ab1 ALTER a SET STATISTICS -1;
-- setting statistics target 0 skips the statistics, without printing any message, so check catalog
ALTER STATISTICS ab1_a_b_stats SET STATISTICS 0;
\d ab1
                Table "public.ab1"
 Column |  Type   | Collation | Nullable | Default 
--------+---------+-----------+----------+---------
 a      | integer |           |          | 
 b      | integer |           |          | 
Statistics objects:
    "public"."ab1_a_b_stats" (ndistinct, dependencies, mcv) ON a, b FROM ab1; STATISTICS 0

ANALYZE ab1;
SELECT stxname, stxdndistinct, stxddependencies, stxdmcv
  FROM pg_statistic_ext s, pg_statistic_ext_data d
 WHERE s.stxname = 'ab1_a_b_stats'
   AND d.stxoid = s.oid;
    stxname    | stxdndistinct | stxddependencies | stxdmcv 
---------------+---------------+------------------+---------
 ab1_a_b_stats |               |                  | 
(1 row)

ALTER STATISTICS ab1_a_b_stats SET STATISTICS -1;
\d+ ab1
                                    Table "public.ab1"
 Column |  Type   | Collation | Nullable | Default | Storage | Stats target | Description 
--------+---------+-----------+----------+---------+---------+--------------+-------------
 a      | integer |           |          |         | plain   |              | 
 b      | integer |           |          |         | plain   |              | 
Statistics objects:
    "public"."ab1_a_b_stats" (ndistinct, dependencies, mcv) ON a, b FROM ab1

-- partial analyze doesn't build stats either
ANALYZE ab1 (a);
WARNING:  statistics object "public.ab1_a_b_stats" could not be computed for relation "public.ab1"
ANALYZE ab1;
DROP TABLE ab1;
ALTER STATISTICS ab1_a_b_stats SET STATISTICS 0;
ERROR:  statistics object "ab1_a_b_stats" does not exist
ALTER STATISTICS IF EXISTS ab1_a_b_stats SET STATISTICS 0;
NOTICE:  statistics object "ab1_a_b_stats" does not exist, skipping
-- Ensure we can build statistics for tables with inheritance.
CREATE TABLE ab1 (a INTEGER, b INTEGER);
CREATE TABLE ab1c () INHERITS (ab1);
INSERT INTO ab1 VALUES (1,1);
CREATE STATISTICS ab1_a_b_stats ON a, b FROM ab1;
ANALYZE ab1;
DROP TABLE ab1 CASCADE;
NOTICE:  drop cascades to table ab1c
-- Verify supported object types for extended statistics
CREATE schema tststats;
CREATE TABLE tststats.t (a int, b int, c text);
CREATE INDEX ti ON tststats.t (a, b);
CREATE SEQUENCE tststats.s;
CREATE VIEW tststats.v AS SELECT * FROM tststats.t;
CREATE MATERIALIZED VIEW tststats.mv AS SELECT * FROM tststats.t;
CREATE TYPE tststats.ty AS (a int, b int, c text);
CREATE FOREIGN DATA WRAPPER extstats_dummy_fdw;
CREATE SERVER extstats_dummy_srv FOREIGN DATA WRAPPER extstats_dummy_fdw;
CREATE FOREIGN TABLE tststats.f (a int, b int, c text) SERVER extstats_dummy_srv;
CREATE TABLE tststats.pt (a int, b int, c text) PARTITION BY RANGE (a, b);
CREATE TABLE tststats.pt1 PARTITION OF tststats.pt FOR VALUES FROM (-10, -10) TO (10, 10);
CREATE STATISTICS tststats.s1 ON a, b FROM tststats.t;
CREATE STATISTICS tststats.s2 ON a, b FROM tststats.ti;
ERROR:  relation "ti" is not a table, foreign table, or materialized view
CREATE STATISTICS tststats.s3 ON a, b FROM tststats.s;
ERROR:  relation "s" is not a table, foreign table, or materialized view
CREATE STATISTICS tststats.s4 ON a, b FROM tststats.v;
ERROR:  relation "v" is not a table, foreign table, or materialized view
CREATE STATISTICS tststats.s5 ON a, b FROM tststats.mv;
CREATE STATISTICS tststats.s6 ON a, b FROM tststats.ty;
ERROR:  relation "ty" is not a table, foreign table, or materialized view
CREATE STATISTICS tststats.s7 ON a, b FROM tststats.f;
CREATE STATISTICS tststats.s8 ON a, b FROM tststats.pt;
CREATE STATISTICS tststats.s9 ON a, b FROM tststats.pt1;
DO $$
DECLARE
	relname text := reltoastrelid::regclass FROM pg_class WHERE oid = 'tststats.t'::regclass;
BEGIN
	EXECUTE 'CREATE STATISTICS tststats.s10 ON a, b FROM ' || relname;
EXCEPTION WHEN wrong_object_type THEN
	RAISE NOTICE 'stats on toast table not created';
END;
$$;
NOTICE:  stats on toast table not created
DROP SCHEMA tststats CASCADE;
NOTICE:  drop cascades to 7 other objects
DETAIL:  drop cascades to table tststats.t
drop cascades to sequence tststats.s
drop cascades to view tststats.v
drop cascades to materialized view tststats.mv
drop cascades to type tststats.ty
drop cascades to foreign table tststats.f
drop cascades to table tststats.pt
DROP FOREIGN DATA WRAPPER extstats_dummy_fdw CASCADE;
NOTICE:  drop cascades to server extstats_dummy_srv
-- n-distinct tests
CREATE TABLE ndistinct (
    filler1 TEXT,
    filler2 NUMERIC,
    a INT,
    b INT,
    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)
       FROM generate_series(1,1000) s(i);
ANALYZE ndistinct;
-- Group Aggregate, due to over-estimate of the number of groups
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
 estimated | actual 
-----------+--------
       100 |     11
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c');
 estimated | actual 
-----------+--------
       100 |     11
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
 estimated | actual 
-----------+--------
       100 |     11
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
 estimated | actual 
-----------+--------
       200 |     11
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
 estimated | actual 
-----------+--------
       200 |     11
(1 row)

-- correct command
CREATE STATISTICS s10 ON a, b, c FROM ndistinct;
ANALYZE ndistinct;
SELECT s.stxkind, d.stxdndistinct
  FROM pg_statistic_ext s, pg_statistic_ext_data d
 WHERE s.stxrelid = 'ndistinct'::regclass
   AND d.stxoid = s.oid;
 stxkind |                    stxdndistinct                    
---------+-----------------------------------------------------
 {d,f,m} | {"3, 4": 11, "3, 6": 11, "4, 6": 11, "3, 4, 6": 11}
(1 row)

-- minor improvement, make sure the ctid does not break the matching
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY ctid, a, b');
 estimated | actual 
-----------+--------
        11 |   1000
(1 row)

-- Hash Aggregate, thanks to estimates improved by the statistic
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
 estimated | actual 
-----------+--------
        11 |     11
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c');
 estimated | actual 
-----------+--------
        11 |     11
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
 estimated | actual 
-----------+--------
        11 |     11
(1 row)

-- last two plans keep using Group Aggregate, because 'd' is not covered
-- by the statistic and while it's NULL-only we assume 200 values for it
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
 estimated | actual 
-----------+--------
       200 |     11
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
 estimated | actual 
-----------+--------
       200 |     11
(1 row)

TRUNCATE TABLE ndistinct;
-- under-estimates when using only per-column statistics
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);
ANALYZE ndistinct;
SELECT s.stxkind, d.stxdndistinct
  FROM pg_statistic_ext s, pg_statistic_ext_data d
 WHERE s.stxrelid = 'ndistinct'::regclass
   AND d.stxoid = s.oid;
 stxkind |                       stxdndistinct                        
---------+------------------------------------------------------------
 {d,f,m} | {"3, 4": 2550, "3, 6": 800, "4, 6": 1632, "3, 4, 6": 5000}
(1 row)

-- correct estimates
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
 estimated | actual 
-----------+--------
      2550 |   2550
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
 estimated | actual 
-----------+--------
      5000 |   5000
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
 estimated | actual 
-----------+--------
      5000 |   5000
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
 estimated | actual 
-----------+--------
      1632 |   1632
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, d');
 estimated | actual 
-----------+--------
       500 |     50
(1 row)

DROP STATISTICS s10;
SELECT s.stxkind, d.stxdndistinct
  FROM pg_statistic_ext s, pg_statistic_ext_data d
 WHERE s.stxrelid = 'ndistinct'::regclass
   AND d.stxoid = s.oid;
 stxkind | stxdndistinct 
---------+---------------
(0 rows)

-- dropping the statistics results in under-estimates
SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b');
 estimated | actual 
-----------+--------
       500 |   2550
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c');
 estimated | actual 
-----------+--------
       500 |   5000
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, b, c, d');
 estimated | actual 
-----------+--------
       500 |   5000
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY b, c, d');
 estimated | actual 
-----------+--------
       500 |   1632
(1 row)

SELECT * FROM check_estimated_rows('SELECT COUNT(*) FROM ndistinct GROUP BY a, d');
 estimated | actual 
-----------+--------
       500 |     50
(1 row)

-- functional dependencies tests
CREATE TABLE functional_dependencies (
    filler1 TEXT,
    filler2 NUMERIC,
    a INT,
    b TEXT,
    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);
ANALYZE functional_dependencies;
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
         8 |      8
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
         1 |      1
(1 row)

-- create statistics
CREATE STATISTICS func_deps_stat (dependencies) ON a, b, c FROM functional_dependencies;
ANALYZE functional_dependencies;
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
         8 |      8
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
         1 |      1
(1 row)

-- a => b, a => c, b => c
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);
ANALYZE functional_dependencies;
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

-- IN
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ''1''');
 estimated | actual 
-----------+--------
         2 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b IN (''1'', ''2'')');
 estimated | actual 
-----------+--------
         4 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b IN (''1'', ''2'')');
 estimated | actual 
-----------+--------
         8 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ''1''');
 estimated | actual 
-----------+--------
         4 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c = 1');
 estimated | actual 
-----------+--------
         1 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c IN (1)');
 estimated | actual 
-----------+--------
         1 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 26, 27, 51, 52, 76, 77) AND b IN (''1'', ''2'', ''26'', ''27'') AND c IN (1, 2)');
 estimated | actual 
-----------+--------
         3 |    400
(1 row)

-- OR clauses referencing the same attribute
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND b = ''1''');
 estimated | actual 
-----------+--------
         2 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND (b = ''1'' OR b = ''2'')');
 estimated | actual 
-----------+--------
         4 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 2 OR a = 51 OR a = 52) AND (b = ''1'' OR b = ''2'')');
 estimated | actual 
-----------+--------
         8 |    200
(1 row)

-- OR clauses referencing different attributes
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR b = ''1'') AND b = ''1''');
 estimated | actual 
-----------+--------
         3 |    100
(1 row)

-- ANY
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ''1''');
 estimated | actual 
-----------+--------
         2 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
         4 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
         8 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = 1');
 estimated | actual 
-----------+--------
         1 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = ANY (ARRAY[1])');
 estimated | actual 
-----------+--------
         1 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 26, 27, 51, 52, 76, 77]) AND b = ANY (ARRAY[''1'', ''2'', ''26'', ''27'']) AND c = ANY (ARRAY[1, 2])');
 estimated | actual 
-----------+--------
         3 |    400
(1 row)

-- ANY with inequalities should not benefit from functional dependencies
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a < ANY (ARRAY[1, 51]) AND b > ''1''');
 estimated | actual 
-----------+--------
      2472 |   2400
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a >= ANY (ARRAY[1, 51]) AND b <= ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
      1441 |   1250
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a <= ANY (ARRAY[1, 2, 51, 52]) AND b >= ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
      3909 |   2550
(1 row)

-- ALL (should not benefit from functional dependencies)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1''])');
 estimated | actual 
-----------+--------
         2 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ALL (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

-- create statistics
CREATE STATISTICS func_deps_stat (dependencies) ON a, b, c FROM functional_dependencies;
ANALYZE functional_dependencies;
-- print the detected dependencies
SELECT dependencies FROM pg_stats_ext WHERE statistics_name = 'func_deps_stat';
                                                dependencies                                                
------------------------------------------------------------------------------------------------------------
 {"3 => 4": 1.000000, "3 => 6": 1.000000, "4 => 6": 1.000000, "3, 4 => 6": 1.000000, "3, 6 => 4": 1.000000}
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

-- IN
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ''1''');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b IN (''1'', ''2'')');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b IN (''1'', ''2'')');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ''1''');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c = 1');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 26, 51, 76) AND b IN (''1'', ''26'') AND c IN (1)');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 26, 27, 51, 52, 76, 77) AND b IN (''1'', ''2'', ''26'', ''27'') AND c IN (1, 2)');
 estimated | actual 
-----------+--------
       400 |    400
(1 row)

-- OR clauses referencing the same attribute
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND b = ''1''');
 estimated | actual 
-----------+--------
        99 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 51) AND (b = ''1'' OR b = ''2'')');
 estimated | actual 
-----------+--------
        99 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR a = 2 OR a = 51 OR a = 52) AND (b = ''1'' OR b = ''2'')');
 estimated | actual 
-----------+--------
       197 |    200
(1 row)

-- OR clauses referencing different attributes are incompatible
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE (a = 1 OR b = ''1'') AND b = ''1''');
 estimated | actual 
-----------+--------
         3 |    100
(1 row)

-- ANY
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ''1''');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 51]) AND b = ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = 1');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 26, 51, 76]) AND b = ANY (ARRAY[''1'', ''26'']) AND c = ANY (ARRAY[1])');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = ANY (ARRAY[1, 2, 26, 27, 51, 52, 76, 77]) AND b = ANY (ARRAY[''1'', ''2'', ''26'', ''27'']) AND c = ANY (ARRAY[1, 2])');
 estimated | actual 
-----------+--------
       400 |    400
(1 row)

-- ANY with inequalities should not benefit from functional dependencies
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a < ANY (ARRAY[1, 51]) AND b > ''1''');
 estimated | actual 
-----------+--------
      2472 |   2400
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a >= ANY (ARRAY[1, 51]) AND b <= ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
      1441 |   1250
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a <= ANY (ARRAY[1, 2, 51, 52]) AND b >= ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
      3909 |   2550
(1 row)

-- ALL (should not benefit from functional dependencies)
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1''])');
 estimated | actual 
-----------+--------
         2 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 51) AND b = ALL (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a IN (1, 2, 51, 52) AND b = ALL (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

-- changing the type of column c causes its single-column stats to be dropped,
-- giving a default estimate of 0.005 * 5000 = 25 for (c = 1); check multiple
-- clauses estimated with functional dependencies does not exceed this
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');
 estimated | actual 
-----------+--------
        25 |     50
(1 row)

ANALYZE functional_dependencies;
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

-- check the ability to use multiple functional dependencies
CREATE TABLE functional_dependencies_multi (
	a INTEGER,
	b INTEGER,
	c INTEGER,
	d INTEGER
)
WITH (autovacuum_enabled = off);
INSERT INTO functional_dependencies_multi (a, b, c, d)
    SELECT
         mod(i,7),
         mod(i,7),
         mod(i,11),
         mod(i,11)
    FROM generate_series(1,5000) s(i);
ANALYZE functional_dependencies_multi;
-- estimates without any functional dependencies
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0');
 estimated | actual 
-----------+--------
       102 |    714
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
 estimated | actual 
-----------+--------
       102 |    714
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
 estimated | actual 
-----------+--------
        41 |    454
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
 estimated | actual 
-----------+--------
         1 |     64
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
 estimated | actual 
-----------+--------
         1 |     64
(1 row)

-- create separate functional dependencies
CREATE STATISTICS functional_dependencies_multi_1 (dependencies) ON a, b FROM functional_dependencies_multi;
CREATE STATISTICS functional_dependencies_multi_2 (dependencies) ON c, d FROM functional_dependencies_multi;
ANALYZE functional_dependencies_multi;
SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0');
 estimated | actual 
-----------+--------
       714 |    714
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND 0 = b');
 estimated | actual 
-----------+--------
       714 |    714
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE c = 0 AND d = 0');
 estimated | actual 
-----------+--------
       454 |    454
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
 estimated | actual 
-----------+--------
        65 |     64
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM functional_dependencies_multi WHERE 0 = a AND b = 0 AND 0 = c AND d = 0');
 estimated | actual 
-----------+--------
        65 |     64
(1 row)

DROP TABLE functional_dependencies_multi;
-- MCV lists
CREATE TABLE mcv_lists (
    filler1 TEXT,
    filler2 NUMERIC,
    a INT,
    b VARCHAR,
    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);
ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
         3 |      4
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
         1 |      1
(1 row)

-- create statistics
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c FROM mcv_lists;
ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
         3 |      4
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
         1 |      1
(1 row)

-- 100 distinct combinations, all in the MCV list
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);
ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 = a AND ''1'' = b');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 1 AND b < ''1''');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 > a AND ''1'' > b');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 0 AND b <= ''0''');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 0 >= a AND ''0'' >= b');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND b < ''1'' AND c < 5');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND ''1'' > b AND 5 > c');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <= ''0'' AND c <= 4');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 4 >= a AND ''0'' >= b AND 4 >= c');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
 estimated | actual 
-----------+--------
       343 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
 estimated | actual 
-----------+--------
       343 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52) AND b IN ( ''1'', ''2'')');
 estimated | actual 
-----------+--------
         8 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52, NULL) AND b IN ( ''1'', ''2'', NULL)');
 estimated | actual 
-----------+--------
         8 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
         8 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[NULL, 1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2'', NULL])');
 estimated | actual 
-----------+--------
         8 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, 2, 3]) AND b IN (''1'', ''2'', ''3'')');
 estimated | actual 
-----------+--------
        26 |    150
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, NULL, 2, 3]) AND b IN (''1'', ''2'', NULL, ''3'')');
 estimated | actual 
-----------+--------
        26 |    150
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3])');
 estimated | actual 
-----------+--------
        10 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3, NULL])');
 estimated | actual 
-----------+--------
        10 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', ''3'') AND c > ANY (ARRAY[1, 2, 3])');
 estimated | actual 
-----------+--------
         1 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', NULL, ''3'') AND c > ANY (ARRAY[1, 2, NULL, 3])');
 estimated | actual 
-----------+--------
         1 |    100
(1 row)

-- create statistics
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c FROM mcv_lists;
ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 = a AND ''1'' = b');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 1 AND b < ''1''');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 1 > a AND ''1'' > b');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 0 AND b <= ''0''');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 0 >= a AND ''0'' >= b');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1'' AND c = 1');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND b < ''1'' AND c < 5');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < 5 AND ''1'' > b AND 5 > c');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= 4 AND b <= ''0'' AND c <= 4');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE 4 >= a AND ''0'' >= b AND 4 >= c');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''1'' OR c = 1 OR d IS NOT NULL');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52) AND b IN ( ''1'', ''2'')');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (1, 2, 51, 52, NULL) AND b IN ( ''1'', ''2'', NULL)');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2''])');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = ANY (ARRAY[NULL, 1, 2, 51, 52]) AND b = ANY (ARRAY[''1'', ''2'', NULL])');
 estimated | actual 
-----------+--------
       200 |    200
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, 2, 3]) AND b IN (''1'', ''2'', ''3'')');
 estimated | actual 
-----------+--------
       150 |    150
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a <= ANY (ARRAY[1, NULL, 2, 3]) AND b IN (''1'', ''2'', NULL, ''3'')');
 estimated | actual 
-----------+--------
       150 |    150
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3])');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND c > ANY (ARRAY[1, 2, 3, NULL])');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', ''3'') AND c > ANY (ARRAY[1, 2, 3])');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a < ALL (ARRAY[4, 5]) AND b IN (''1'', ''2'', NULL, ''3'') AND c > ANY (ARRAY[1, 2, NULL, 3])');
 estimated | actual 
-----------+--------
       100 |    100
(1 row)

-- check change of unrelated column type does not reset the MCV statistics
ALTER TABLE mcv_lists ALTER COLUMN d TYPE VARCHAR(64);
SELECT d.stxdmcv IS NOT NULL
  FROM pg_statistic_ext s, pg_statistic_ext_data d
 WHERE s.stxname = 'mcv_lists_stats'
   AND d.stxoid = s.oid;
 ?column? 
----------
 t
(1 row)

-- check change of column type resets the MCV statistics
ALTER TABLE mcv_lists ALTER COLUMN c TYPE numeric;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 AND b = ''1''');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

-- 100 distinct combinations with NULL values, all in the MCV list
TRUNCATE mcv_lists;
DROP STATISTICS mcv_lists_stats;
INSERT INTO mcv_lists (a, b, c, filler1)
     SELECT
         (CASE WHEN mod(i,100) = 1 THEN NULL ELSE mod(i,100) END),
         (CASE WHEN mod(i,50) = 1  THEN NULL ELSE mod(i,50) END),
         (CASE WHEN mod(i,25) = 1  THEN NULL ELSE mod(i,25) END),
         i
     FROM generate_series(1,5000) s(i);
ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL AND c IS NULL');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NOT NULL');
 estimated | actual 
-----------+--------
        49 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NOT NULL AND b IS NULL AND c IS NOT NULL');
 estimated | actual 
-----------+--------
        95 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (0, 1) AND b IN (''0'', ''1'')');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

-- create statistics
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, c FROM mcv_lists;
ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NULL AND c IS NULL');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND b IS NOT NULL');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NOT NULL AND b IS NULL AND c IS NOT NULL');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IN (0, 1) AND b IN (''0'', ''1'')');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

-- 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);
ANALYZE mcv_lists;
SELECT m.*
  FROM pg_statistic_ext s, pg_statistic_ext_data d,
       pg_mcv_list_items(d.stxdmcv) m
 WHERE s.stxname = 'mcv_lists_stats'
   AND d.stxoid = s.oid;
 index | values  |  nulls  | frequency | base_frequency 
-------+---------+---------+-----------+----------------
     0 | {1,2,3} | {f,f,f} |         1 |              1
(1 row)

-- 2 distinct combinations with NULL values, all in the MCV list
TRUNCATE mcv_lists;
DROP STATISTICS mcv_lists_stats;
INSERT INTO mcv_lists (a, b, c, d)
     SELECT
         NULL, -- always NULL
         (CASE WHEN mod(i,2) = 0 THEN NULL ELSE 'x' END),
         (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);
ANALYZE mcv_lists;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE b = ''x'' OR d = ''x''');
 estimated | actual 
-----------+--------
      3750 |   2500
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''x'' OR d = ''x''');
 estimated | actual 
-----------+--------
      3750 |   2500
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND (b = ''x'' OR d = ''x'')');
 estimated | actual 
-----------+--------
      3750 |   2500
(1 row)

-- create statistics
CREATE STATISTICS mcv_lists_stats (mcv) ON a, b, d FROM mcv_lists;
ANALYZE mcv_lists;
-- test pg_mcv_list_items with MCV list containing variable-length data and NULLs
SELECT m.*
  FROM pg_statistic_ext s, pg_statistic_ext_data d,
       pg_mcv_list_items(d.stxdmcv) m
 WHERE s.stxname = 'mcv_lists_stats'
   AND d.stxoid = s.oid;
 index |      values      |  nulls  | frequency | base_frequency 
-------+------------------+---------+-----------+----------------
     0 | {NULL,x,x}       | {t,f,f} |       0.5 |           0.25
     1 | {NULL,NULL,NULL} | {t,t,t} |       0.5 |           0.25
(2 rows)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE b = ''x'' OR d = ''x''');
 estimated | actual 
-----------+--------
      2500 |   2500
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a = 1 OR b = ''x'' OR d = ''x''');
 estimated | actual 
-----------+--------
      2500 |   2500
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists WHERE a IS NULL AND (b = ''x'' OR d = ''x'')');
 estimated | actual 
-----------+--------
      2500 |   2500
(1 row)

-- mcv with pass-by-ref fixlen types, e.g. uuid
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,
         md5(mod(i,50)::text)::uuid,
         md5(mod(i,25)::text)::uuid
     FROM generate_series(1,5000) s(i);
ANALYZE mcv_lists_uuid;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc'' AND b = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc''');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc'' AND b = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc'' AND c = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc''');
 estimated | actual 
-----------+--------
         1 |     50
(1 row)

CREATE STATISTICS mcv_lists_uuid_stats (mcv) ON a, b, c
  FROM mcv_lists_uuid;
ANALYZE mcv_lists_uuid;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc'' AND b = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc''');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_uuid WHERE a = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc'' AND b = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc'' AND c = ''1679091c-5a88-0faf-6fb5-e6087eb1b2dc''');
 estimated | actual 
-----------+--------
        50 |     50
(1 row)

DROP TABLE mcv_lists_uuid;
-- mcv with arrays
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)],
         ARRAY[(i/100-1)::numeric/1000, (i/100)::numeric/1000, (i/100+1)::numeric/1000],
         ARRAY[(i/100-1), i/100, (i/100+1)]
     FROM generate_series(1,5000) s(i);
CREATE STATISTICS mcv_lists_arrays_stats (mcv) ON a, b, c
  FROM mcv_lists_arrays;
ANALYZE mcv_lists_arrays;
-- mcv with bool
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);
ANALYZE mcv_lists_bool;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE a AND b AND c');
 estimated | actual 
-----------+--------
       156 |   1250
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND c');
 estimated | actual 
-----------+--------
       156 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND NOT b AND c');
 estimated | actual 
-----------+--------
       469 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND NOT c');
 estimated | actual 
-----------+--------
      1094 |      0
(1 row)

CREATE STATISTICS mcv_lists_bool_stats (mcv) ON a, b, c
  FROM 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 
-----------+--------
      1250 |   1250
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND c');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND NOT b AND c');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_bool WHERE NOT a AND b AND NOT c');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

-- mcv covering just a small fraction of data
CREATE TABLE mcv_lists_partial (
    a INT,
    b INT,
    c INT
);
-- 10 frequent groups, each with 100 elements
INSERT INTO mcv_lists_partial (a, b, c)
     SELECT
         mod(i,10),
         mod(i,10),
         mod(i,10)
     FROM generate_series(0,999) s(i);
-- 100 groups that will make it to the MCV list (includes the 10 frequent ones)
INSERT INTO mcv_lists_partial (a, b, c)
     SELECT
         i,
         i,
         i
     FROM generate_series(0,99) s(i);
-- 4000 groups in total, most of which won't make it (just a single item)
INSERT INTO mcv_lists_partial (a, b, c)
     SELECT
         i,
         i,
         i
     FROM generate_series(0,3999) s(i);
ANALYZE mcv_lists_partial;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 0');
 estimated | actual 
-----------+--------
         1 |    102
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 0');
 estimated | actual 
-----------+--------
       300 |    102
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 AND b = 10 AND c = 10');
 estimated | actual 
-----------+--------
         1 |      2
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 OR b = 10 OR c = 10');
 estimated | actual 
-----------+--------
         6 |      2
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 10');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 10');
 estimated | actual 
-----------+--------
       204 |    104
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0 AND c = 0) OR (a = 1 AND b = 1 AND c = 1) OR (a = 2 AND b = 2 AND c = 2)');
 estimated | actual 
-----------+--------
         1 |    306
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0) OR (a = 0 AND c = 0) OR (b = 0 AND c = 0)');
 estimated | actual 
-----------+--------
         6 |    102
(1 row)

CREATE STATISTICS mcv_lists_partial_stats (mcv) ON a, b, c
  FROM mcv_lists_partial;
ANALYZE mcv_lists_partial;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 0');
 estimated | actual 
-----------+--------
       102 |    102
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 0');
 estimated | actual 
-----------+--------
        96 |    102
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 AND b = 10 AND c = 10');
 estimated | actual 
-----------+--------
         2 |      2
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 10 OR b = 10 OR c = 10');
 estimated | actual 
-----------+--------
         2 |      2
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 AND b = 0 AND c = 10');
 estimated | actual 
-----------+--------
         1 |      0
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE a = 0 OR b = 0 OR c = 10');
 estimated | actual 
-----------+--------
       102 |    104
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0 AND c = 0) OR (a = 1 AND b = 1 AND c = 1) OR (a = 2 AND b = 2 AND c = 2)');
 estimated | actual 
-----------+--------
       306 |    306
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_partial WHERE (a = 0 AND b = 0) OR (a = 0 AND c = 0) OR (b = 0 AND c = 0)');
 estimated | actual 
-----------+--------
       108 |    102
(1 row)

DROP TABLE mcv_lists_partial;
-- check the ability to use multiple MCV lists
CREATE TABLE mcv_lists_multi (
	a INTEGER,
	b INTEGER,
	c INTEGER,
	d INTEGER
)
WITH (autovacuum_enabled = off);
INSERT INTO mcv_lists_multi (a, b, c, d)
    SELECT
         mod(i,5),
         mod(i,5),
         mod(i,7),
         mod(i,7)
    FROM generate_series(1,5000) s(i);
ANALYZE mcv_lists_multi;
-- estimates without any mcv statistics
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0');
 estimated | actual 
-----------+--------
       200 |   1000
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE c = 0 AND d = 0');
 estimated | actual 
-----------+--------
       102 |    714
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 AND c = 0');
 estimated | actual 
-----------+--------
       143 |    142
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 OR c = 0');
 estimated | actual 
-----------+--------
      1571 |   1572
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
 estimated | actual 
-----------+--------
         4 |    142
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE (a = 0 AND b = 0) OR (c = 0 AND d = 0)');
 estimated | actual 
-----------+--------
       298 |   1572
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 OR b = 0 OR c = 0 OR d = 0');
 estimated | actual 
-----------+--------
      2649 |   1572
(1 row)

-- create separate MCV statistics
CREATE STATISTICS mcv_lists_multi_1 (mcv) ON a, b FROM mcv_lists_multi;
CREATE STATISTICS mcv_lists_multi_2 (mcv) ON c, d FROM mcv_lists_multi;
ANALYZE mcv_lists_multi;
SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0');
 estimated | actual 
-----------+--------
      1000 |   1000
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE c = 0 AND d = 0');
 estimated | actual 
-----------+--------
       714 |    714
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 AND c = 0');
 estimated | actual 
-----------+--------
       143 |    142
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE b = 0 OR c = 0');
 estimated | actual 
-----------+--------
      1571 |   1572
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 AND b = 0 AND c = 0 AND d = 0');
 estimated | actual 
-----------+--------
       143 |    142
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE (a = 0 AND b = 0) OR (c = 0 AND d = 0)');
 estimated | actual 
-----------+--------
      1571 |   1572
(1 row)

SELECT * FROM check_estimated_rows('SELECT * FROM mcv_lists_multi WHERE a = 0 OR b = 0 OR c = 0 OR d = 0');
 estimated | actual 
-----------+--------
      1571 |   1572
(1 row)

DROP TABLE mcv_lists_multi;
-- Permission tests. Users should not be able to see specific data values in
-- the extended statistics, if they lack permission to see those values in
-- the underlying table.
--
-- Currently this is only relevant for MCV stats.
CREATE SCHEMA tststats;
CREATE TABLE tststats.priv_test_tbl (
    a int,
    b int
);
INSERT INTO tststats.priv_test_tbl
     SELECT mod(i,5), mod(i,10) FROM generate_series(1,100) s(i);
CREATE STATISTICS tststats.priv_test_stats (mcv) ON a, b
  FROM tststats.priv_test_tbl;
ANALYZE tststats.priv_test_tbl;
-- User with no access
CREATE USER regress_stats_user1;
GRANT USAGE ON SCHEMA tststats TO regress_stats_user1;
SET SESSION AUTHORIZATION regress_stats_user1;
SELECT * FROM tststats.priv_test_tbl; -- Permission denied
ERROR:  permission denied for table priv_test_tbl
-- Attempt to gain access using a leaky operator
CREATE FUNCTION op_leak(int, int) RETURNS bool
    AS 'BEGIN RAISE NOTICE ''op_leak => %, %'', $1, $2; RETURN $1 < $2; END'
    LANGUAGE plpgsql;
CREATE OPERATOR <<< (procedure = op_leak, leftarg = int, rightarg = int,
                     restrict = scalarltsel);
SELECT * FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Permission denied
ERROR:  permission denied for table priv_test_tbl
DELETE FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Permission denied
ERROR:  permission denied for table priv_test_tbl
-- Grant access via a security barrier view, but hide all data
RESET SESSION AUTHORIZATION;
CREATE VIEW tststats.priv_test_view WITH (security_barrier=true)
    AS SELECT * FROM tststats.priv_test_tbl WHERE false;
GRANT SELECT, DELETE ON tststats.priv_test_view TO regress_stats_user1;
-- Should now have access via the view, but see nothing and leak nothing
SET SESSION AUTHORIZATION regress_stats_user1;
SELECT * FROM tststats.priv_test_view WHERE a <<< 0 AND b <<< 0; -- Should not leak
 a | b 
---+---
(0 rows)

DELETE FROM tststats.priv_test_view WHERE a <<< 0 AND b <<< 0; -- Should not leak
-- Grant table access, but hide all data with RLS
RESET SESSION AUTHORIZATION;
ALTER TABLE tststats.priv_test_tbl ENABLE ROW LEVEL SECURITY;
GRANT SELECT, DELETE ON tststats.priv_test_tbl TO regress_stats_user1;
-- Should now have direct table access, but see nothing and leak nothing
SET SESSION AUTHORIZATION regress_stats_user1;
SELECT * FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Should not leak
 a | b 
---+---
(0 rows)

DELETE FROM tststats.priv_test_tbl WHERE a <<< 0 AND b <<< 0; -- Should not leak
-- Tidy up
DROP OPERATOR <<< (int, int);
DROP FUNCTION op_leak(int, int);
RESET SESSION AUTHORIZATION;
DROP SCHEMA tststats CASCADE;
NOTICE:  drop cascades to 2 other objects
DETAIL:  drop cascades to table tststats.priv_test_tbl
drop cascades to view tststats.priv_test_view
DROP USER regress_stats_user1;