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|
--
-- 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)
-- 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)
|