--
-- Tests for the planner's "equivalence class" mechanism
--
-- One thing that's not tested well during normal querying is the logic
-- for handling "broken" ECs.  This is because an EC can only become broken
-- if its underlying btree operator family doesn't include a complete set
-- of cross-type equality operators.  There are not (and should not be)
-- any such families built into Postgres; so we have to hack things up
-- to create one.  We do this by making two alias types that are really
-- int8 (so we need no new C code) and adding only some operators for them
-- into the standard integer_ops opfamily.
create type int8alias1;
create function int8alias1in(cstring) returns int8alias1
  strict immutable language internal as 'int8in';
NOTICE:  return type int8alias1 is only a shell
create function int8alias1out(int8alias1) returns cstring
  strict immutable language internal as 'int8out';
NOTICE:  argument type int8alias1 is only a shell
create type int8alias1 (
    input = int8alias1in,
    output = int8alias1out,
    like = int8
);
create type int8alias2;
create function int8alias2in(cstring) returns int8alias2
  strict immutable language internal as 'int8in';
NOTICE:  return type int8alias2 is only a shell
create function int8alias2out(int8alias2) returns cstring
  strict immutable language internal as 'int8out';
NOTICE:  argument type int8alias2 is only a shell
create type int8alias2 (
    input = int8alias2in,
    output = int8alias2out,
    like = int8
);
create cast (int8 as int8alias1) without function;
create cast (int8 as int8alias2) without function;
create cast (int8alias1 as int8) without function;
create cast (int8alias2 as int8) without function;
create function int8alias1eq(int8alias1, int8alias1) returns bool
  strict immutable language internal as 'int8eq';
create operator = (
    procedure = int8alias1eq,
    leftarg = int8alias1, rightarg = int8alias1,
    commutator = =,
    restrict = eqsel, join = eqjoinsel,
    merges
);
alter operator family integer_ops using btree add
  operator 3 = (int8alias1, int8alias1);
create function int8alias2eq(int8alias2, int8alias2) returns bool
  strict immutable language internal as 'int8eq';
create operator = (
    procedure = int8alias2eq,
    leftarg = int8alias2, rightarg = int8alias2,
    commutator = =,
    restrict = eqsel, join = eqjoinsel,
    merges
);
alter operator family integer_ops using btree add
  operator 3 = (int8alias2, int8alias2);
create function int8alias1eq(int8, int8alias1) returns bool
  strict immutable language internal as 'int8eq';
create operator = (
    procedure = int8alias1eq,
    leftarg = int8, rightarg = int8alias1,
    restrict = eqsel, join = eqjoinsel,
    merges
);
alter operator family integer_ops using btree add
  operator 3 = (int8, int8alias1);
create function int8alias1eq(int8alias1, int8alias2) returns bool
  strict immutable language internal as 'int8eq';
create operator = (
    procedure = int8alias1eq,
    leftarg = int8alias1, rightarg = int8alias2,
    restrict = eqsel, join = eqjoinsel,
    merges
);
alter operator family integer_ops using btree add
  operator 3 = (int8alias1, int8alias2);
create function int8alias1lt(int8alias1, int8alias1) returns bool
  strict immutable language internal as 'int8lt';
create operator < (
    procedure = int8alias1lt,
    leftarg = int8alias1, rightarg = int8alias1
);
alter operator family integer_ops using btree add
  operator 1 < (int8alias1, int8alias1);
create function int8alias1cmp(int8, int8alias1) returns int
  strict immutable language internal as 'btint8cmp';
alter operator family integer_ops using btree add
  function 1 int8alias1cmp (int8, int8alias1);
create table ec0 (ff int8 primary key, f1 int8, f2 int8);
create table ec1 (ff int8 primary key, f1 int8alias1, f2 int8alias2);
create table ec2 (xf int8 primary key, x1 int8alias1, x2 int8alias2);
-- for the moment we only want to look at nestloop plans
set enable_hashjoin = off;
set enable_mergejoin = off;
--
-- Note that for cases where there's a missing operator, we don't care so
-- much whether the plan is ideal as that we don't fail or generate an
-- outright incorrect plan.
--
explain (costs off)
  select * from ec0 where ff = f1 and f1 = '42'::int8;
            QUERY PLAN             
-----------------------------------
 Index Scan using ec0_pkey on ec0
   Index Cond: (ff = '42'::bigint)
   Filter: (f1 = '42'::bigint)
(3 rows)

explain (costs off)
  select * from ec0 where ff = f1 and f1 = '42'::int8alias1;
              QUERY PLAN               
---------------------------------------
 Index Scan using ec0_pkey on ec0
   Index Cond: (ff = '42'::int8alias1)
   Filter: (f1 = '42'::int8alias1)
(3 rows)

explain (costs off)
  select * from ec1 where ff = f1 and f1 = '42'::int8alias1;
              QUERY PLAN               
---------------------------------------
 Index Scan using ec1_pkey on ec1
   Index Cond: (ff = '42'::int8alias1)
   Filter: (f1 = '42'::int8alias1)
(3 rows)

explain (costs off)
  select * from ec1 where ff = f1 and f1 = '42'::int8alias2;
                    QUERY PLAN                     
---------------------------------------------------
 Seq Scan on ec1
   Filter: ((ff = f1) AND (f1 = '42'::int8alias2))
(2 rows)

explain (costs off)
  select * from ec1, ec2 where ff = x1 and ff = '42'::int8;
                            QUERY PLAN                             
-------------------------------------------------------------------
 Nested Loop
   Join Filter: (ec1.ff = ec2.x1)
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: ((ff = '42'::bigint) AND (ff = '42'::bigint))
   ->  Seq Scan on ec2
(5 rows)

explain (costs off)
  select * from ec1, ec2 where ff = x1 and ff = '42'::int8alias1;
                 QUERY PLAN                  
---------------------------------------------
 Nested Loop
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: (ff = '42'::int8alias1)
   ->  Seq Scan on ec2
         Filter: (x1 = '42'::int8alias1)
(5 rows)

explain (costs off)
  select * from ec1, ec2 where ff = x1 and '42'::int8 = x1;
               QUERY PLAN                
-----------------------------------------
 Nested Loop
   Join Filter: (ec1.ff = ec2.x1)
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: (ff = '42'::bigint)
   ->  Seq Scan on ec2
         Filter: ('42'::bigint = x1)
(6 rows)

explain (costs off)
  select * from ec1, ec2 where ff = x1 and x1 = '42'::int8alias1;
                 QUERY PLAN                  
---------------------------------------------
 Nested Loop
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: (ff = '42'::int8alias1)
   ->  Seq Scan on ec2
         Filter: (x1 = '42'::int8alias1)
(5 rows)

explain (costs off)
  select * from ec1, ec2 where ff = x1 and x1 = '42'::int8alias2;
               QUERY PLAN                
-----------------------------------------
 Nested Loop
   ->  Seq Scan on ec2
         Filter: (x1 = '42'::int8alias2)
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: (ff = ec2.x1)
(5 rows)

create unique index ec1_expr1 on ec1((ff + 1));
create unique index ec1_expr2 on ec1((ff + 2 + 1));
create unique index ec1_expr3 on ec1((ff + 3 + 1));
create unique index ec1_expr4 on ec1((ff + 4));
explain (costs off)
  select * from ec1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss1
  where ss1.x = ec1.f1 and ec1.ff = 42::int8;
                     QUERY PLAN                      
-----------------------------------------------------
 Nested Loop
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: (ff = '42'::bigint)
   ->  Append
         ->  Index Scan using ec1_expr2 on ec1 ec1_1
               Index Cond: (((ff + 2) + 1) = ec1.f1)
         ->  Index Scan using ec1_expr3 on ec1 ec1_2
               Index Cond: (((ff + 3) + 1) = ec1.f1)
         ->  Index Scan using ec1_expr4 on ec1 ec1_3
               Index Cond: ((ff + 4) = ec1.f1)
(10 rows)

explain (costs off)
  select * from ec1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss1
  where ss1.x = ec1.f1 and ec1.ff = 42::int8 and ec1.ff = ec1.f1;
                            QUERY PLAN                             
-------------------------------------------------------------------
 Nested Loop
   Join Filter: ((((ec1_1.ff + 2) + 1)) = ec1.f1)
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: ((ff = '42'::bigint) AND (ff = '42'::bigint))
         Filter: (ff = f1)
   ->  Append
         ->  Index Scan using ec1_expr2 on ec1 ec1_1
               Index Cond: (((ff + 2) + 1) = '42'::bigint)
         ->  Index Scan using ec1_expr3 on ec1 ec1_2
               Index Cond: (((ff + 3) + 1) = '42'::bigint)
         ->  Index Scan using ec1_expr4 on ec1 ec1_3
               Index Cond: ((ff + 4) = '42'::bigint)
(12 rows)

explain (costs off)
  select * from ec1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss2
  where ss1.x = ec1.f1 and ss1.x = ss2.x and ec1.ff = 42::int8;
                             QUERY PLAN                              
---------------------------------------------------------------------
 Nested Loop
   ->  Nested Loop
         ->  Index Scan using ec1_pkey on ec1
               Index Cond: (ff = '42'::bigint)
         ->  Append
               ->  Index Scan using ec1_expr2 on ec1 ec1_1
                     Index Cond: (((ff + 2) + 1) = ec1.f1)
               ->  Index Scan using ec1_expr3 on ec1 ec1_2
                     Index Cond: (((ff + 3) + 1) = ec1.f1)
               ->  Index Scan using ec1_expr4 on ec1 ec1_3
                     Index Cond: ((ff + 4) = ec1.f1)
   ->  Append
         ->  Index Scan using ec1_expr2 on ec1 ec1_4
               Index Cond: (((ff + 2) + 1) = (((ec1_1.ff + 2) + 1)))
         ->  Index Scan using ec1_expr3 on ec1 ec1_5
               Index Cond: (((ff + 3) + 1) = (((ec1_1.ff + 2) + 1)))
         ->  Index Scan using ec1_expr4 on ec1 ec1_6
               Index Cond: ((ff + 4) = (((ec1_1.ff + 2) + 1)))
(18 rows)

-- let's try that as a mergejoin
set enable_mergejoin = on;
set enable_nestloop = off;
explain (costs off)
  select * from ec1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss2
  where ss1.x = ec1.f1 and ss1.x = ss2.x and ec1.ff = 42::int8;
                           QUERY PLAN                            
-----------------------------------------------------------------
 Merge Join
   Merge Cond: ((((ec1_4.ff + 2) + 1)) = (((ec1_1.ff + 2) + 1)))
   ->  Merge Append
         Sort Key: (((ec1_4.ff + 2) + 1))
         ->  Index Scan using ec1_expr2 on ec1 ec1_4
         ->  Index Scan using ec1_expr3 on ec1 ec1_5
         ->  Index Scan using ec1_expr4 on ec1 ec1_6
   ->  Materialize
         ->  Merge Join
               Merge Cond: ((((ec1_1.ff + 2) + 1)) = ec1.f1)
               ->  Merge Append
                     Sort Key: (((ec1_1.ff + 2) + 1))
                     ->  Index Scan using ec1_expr2 on ec1 ec1_1
                     ->  Index Scan using ec1_expr3 on ec1 ec1_2
                     ->  Index Scan using ec1_expr4 on ec1 ec1_3
               ->  Sort
                     Sort Key: ec1.f1 USING <
                     ->  Index Scan using ec1_pkey on ec1
                           Index Cond: (ff = '42'::bigint)
(19 rows)

-- check partially indexed scan
set enable_nestloop = on;
set enable_mergejoin = off;
drop index ec1_expr3;
explain (costs off)
  select * from ec1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss1
  where ss1.x = ec1.f1 and ec1.ff = 42::int8;
                     QUERY PLAN                      
-----------------------------------------------------
 Nested Loop
   ->  Index Scan using ec1_pkey on ec1
         Index Cond: (ff = '42'::bigint)
   ->  Append
         ->  Index Scan using ec1_expr2 on ec1 ec1_1
               Index Cond: (((ff + 2) + 1) = ec1.f1)
         ->  Seq Scan on ec1 ec1_2
               Filter: (((ff + 3) + 1) = ec1.f1)
         ->  Index Scan using ec1_expr4 on ec1 ec1_3
               Index Cond: ((ff + 4) = ec1.f1)
(10 rows)

-- let's try that as a mergejoin
set enable_mergejoin = on;
set enable_nestloop = off;
explain (costs off)
  select * from ec1,
    (select ff + 1 as x from
       (select ff + 2 as ff from ec1
        union all
        select ff + 3 as ff from ec1) ss0
     union all
     select ff + 4 as x from ec1) as ss1
  where ss1.x = ec1.f1 and ec1.ff = 42::int8;
                     QUERY PLAN                      
-----------------------------------------------------
 Merge Join
   Merge Cond: ((((ec1_1.ff + 2) + 1)) = ec1.f1)
   ->  Merge Append
         Sort Key: (((ec1_1.ff + 2) + 1))
         ->  Index Scan using ec1_expr2 on ec1 ec1_1
         ->  Sort
               Sort Key: (((ec1_2.ff + 3) + 1))
               ->  Seq Scan on ec1 ec1_2
         ->  Index Scan using ec1_expr4 on ec1 ec1_3
   ->  Sort
         Sort Key: ec1.f1 USING <
         ->  Index Scan using ec1_pkey on ec1
               Index Cond: (ff = '42'::bigint)
(13 rows)

-- check effects of row-level security
set enable_nestloop = on;
set enable_mergejoin = off;
alter table ec1 enable row level security;
create policy p1 on ec1 using (f1 < '5'::int8alias1);
create user regress_user_ectest;
grant select on ec0 to regress_user_ectest;
grant select on ec1 to regress_user_ectest;
-- without any RLS, we'll treat {a.ff, b.ff, 43} as an EquivalenceClass
explain (costs off)
  select * from ec0 a, ec1 b
  where a.ff = b.ff and a.ff = 43::bigint::int8alias1;
                 QUERY PLAN                  
---------------------------------------------
 Nested Loop
   ->  Index Scan using ec0_pkey on ec0 a
         Index Cond: (ff = '43'::int8alias1)
   ->  Index Scan using ec1_pkey on ec1 b
         Index Cond: (ff = '43'::int8alias1)
(5 rows)

set session authorization regress_user_ectest;
-- with RLS active, the non-leakproof a.ff = 43 clause is not treated
-- as a suitable source for an EquivalenceClass; currently, this is true
-- even though the RLS clause has nothing to do directly with the EC
explain (costs off)
  select * from ec0 a, ec1 b
  where a.ff = b.ff and a.ff = 43::bigint::int8alias1;
                 QUERY PLAN                  
---------------------------------------------
 Nested Loop
   ->  Index Scan using ec0_pkey on ec0 a
         Index Cond: (ff = '43'::int8alias1)
   ->  Index Scan using ec1_pkey on ec1 b
         Index Cond: (ff = a.ff)
         Filter: (f1 < '5'::int8alias1)
(6 rows)

reset session authorization;
revoke select on ec0 from regress_user_ectest;
revoke select on ec1 from regress_user_ectest;
drop user regress_user_ectest;
-- check that X=X is converted to X IS NOT NULL when appropriate
explain (costs off)
  select * from tenk1 where unique1 = unique1 and unique2 = unique2;
                         QUERY PLAN                          
-------------------------------------------------------------
 Seq Scan on tenk1
   Filter: ((unique1 IS NOT NULL) AND (unique2 IS NOT NULL))
(2 rows)

-- Test that broken ECs are processed correctly during self join removal.
-- Disable merge joins so that we don't get an error about missing commutator.
-- Test both orientations of the join clause, because only one of them breaks
-- the EC.
set enable_mergejoin to off;
explain (costs off)
  select * from ec0 m join ec0 n on m.ff = n.ff
  join ec1 p on m.ff + n.ff = p.f1;
              QUERY PLAN               
---------------------------------------
 Nested Loop
   Join Filter: ((n.ff + n.ff) = p.f1)
   ->  Seq Scan on ec0 n
   ->  Materialize
         ->  Seq Scan on ec1 p
(5 rows)

explain (costs off)
  select * from ec0 m join ec0 n on m.ff = n.ff
  join ec1 p on p.f1::int8 = (m.ff + n.ff)::int8alias1;
                          QUERY PLAN                           
---------------------------------------------------------------
 Nested Loop
   Join Filter: ((p.f1)::bigint = ((n.ff + n.ff))::int8alias1)
   ->  Seq Scan on ec0 n
   ->  Materialize
         ->  Seq Scan on ec1 p
(5 rows)

reset enable_mergejoin;
-- this could be converted, but isn't at present
explain (costs off)
  select * from tenk1 where unique1 = unique1 or unique2 = unique2;
                       QUERY PLAN                       
--------------------------------------------------------
 Seq Scan on tenk1
   Filter: ((unique1 = unique1) OR (unique2 = unique2))
(2 rows)

-- check that we recognize equivalence with dummy domains in the way
create temp table undername (f1 name, f2 int);
create temp view overview as
  select f1::information_schema.sql_identifier as sqli, f2 from undername;
explain (costs off)  -- this should not require a sort
  select * from overview where sqli = 'foo' order by sqli;
          QUERY PLAN          
------------------------------
 Seq Scan on undername
   Filter: (f1 = 'foo'::name)
(2 rows)