open-dsi
/
postgres
mirror of https://github.com/postgres/postgres
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fix thinko in new logic about pushing down non-nullability constraints:

Browse Source 
constraints appearing in outer-join qualification clauses are restricted
as to when and where they can be pushed down.  Add regression test
to catch future errors in this area.
WIN32_DEV
Tom Lane 23 years ago
parent ec8f0e82ef
commit 8a4fdce9f2
3 changed files with 192 additions and 8 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 38
      src/backend/optimizer/prep/prepjointree.c
  2. 123
      src/test/regress/expected/join.out
  3. 39
      src/test/regress/sql/join.sql

38
src/backend/optimizer/prep/prepjointree.c
Unescape View File

@ -16,7 +16,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.5 2003/02/09 23:57:19 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.6 2003/02/10 17:08:50 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -694,23 +694,45 @@ reduce_outer_joins_pass2(Node *jtnode,
/* Only recurse if there's more to do below here */
if (left_state->contains_outer || right_state->contains_outer)
{
Relids local_nonnullable;
Relids pass_nonnullable;
/*
* Scan join quals to see if we can add any nonnullability
* constraints. (Okay to do this even if join is still outer.)
* If this join is (now) inner, we can add any nonnullability
* constraints its quals provide to those we got from above.
* But if it is outer, we can only pass down the local constraints
* into the nullable side, because an outer join never eliminates
* any rows from its non-nullable side. If it's a FULL join then
* it doesn't eliminate anything from either side.
*/
pass_nonnullable = find_nonnullable_rels(j->quals, true);
pass_nonnullable = bms_add_members(pass_nonnullable,
nonnullable_rels);
/* And recurse as needed */
if (jointype != JOIN_FULL)
{
local_nonnullable = find_nonnullable_rels(j->quals, true);
local_nonnullable = bms_add_members(local_nonnullable,
nonnullable_rels);
}
else
local_nonnullable = NULL; /* no use in calculating it */
if (left_state->contains_outer)
{
if (jointype == JOIN_INNER || jointype == JOIN_RIGHT)
pass_nonnullable = local_nonnullable;
else
pass_nonnullable = nonnullable_rels;
reduce_outer_joins_pass2(j->larg, left_state, parse,
pass_nonnullable);
}
if (right_state->contains_outer)
{
if (jointype == JOIN_INNER || jointype == JOIN_LEFT)
pass_nonnullable = local_nonnullable;
else
pass_nonnullable = nonnullable_rels;
reduce_outer_joins_pass2(j->rarg, right_state, parse,
pass_nonnullable);
bms_free(pass_nonnullable);
}
bms_free(local_nonnullable);
}
}
else

123
src/test/regress/expected/join.out
Unescape View File

@ -2004,6 +2004,129 @@ NATURAL FULL JOIN
dd | | 42 | 2 |
(4 rows)
-- Test for propagation of nullability constraints into sub-joins
create temp table x (x1 int, x2 int);
insert into x values (1,11);
insert into x values (2,22);
insert into x values (3,null);
insert into x values (4,44);
insert into x values (5,null);
create temp table y (y1 int, y2 int);
insert into y values (1,111);
insert into y values (2,222);
insert into y values (3,333);
insert into y values (4,null);
select * from x;
x1 | x2
----+----
1 | 11
2 | 22
3 |
4 | 44
5 |
(5 rows)
select * from y;
y1 | y2
----+-----
1 | 111
2 | 222
3 | 333
4 |
(4 rows)
select * from x left join y on (x1 = y1 and x2 is not null);
x1 | x2 | y1 | y2
----+----+----+-----
1 | 11 | 1 | 111
2 | 22 | 2 | 222
3 | | |
4 | 44 | 4 |
5 | | |
(5 rows)
select * from x left join y on (x1 = y1 and y2 is not null);
x1 | x2 | y1 | y2
----+----+----+-----
1 | 11 | 1 | 111
2 | 22 | 2 | 222
3 | | 3 | 333
4 | 44 | |
5 | | |
(5 rows)
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1);
x1 | x2 | y1 | y2 | xx1 | xx2
----+----+----+-----+-----+-----
1 | 11 | 1 | 111 | 1 | 11
2 | 22 | 2 | 222 | 2 | 22
3 | | 3 | 333 | 3 |
4 | 44 | 4 | | 4 | 44
5 | | | | 5 |
(5 rows)
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1 and x2 is not null);
x1 | x2 | y1 | y2 | xx1 | xx2
----+----+----+-----+-----+-----
1 | 11 | 1 | 111 | 1 | 11
2 | 22 | 2 | 222 | 2 | 22
3 | | 3 | 333 | |
4 | 44 | 4 | | 4 | 44
5 | | | | |
(5 rows)
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1 and y2 is not null);
x1 | x2 | y1 | y2 | xx1 | xx2
----+----+----+-----+-----+-----
1 | 11 | 1 | 111 | 1 | 11
2 | 22 | 2 | 222 | 2 | 22
3 | | 3 | 333 | 3 |
4 | 44 | 4 | | |
5 | | | | |
(5 rows)
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1 and xx2 is not null);
x1 | x2 | y1 | y2 | xx1 | xx2
----+----+----+-----+-----+-----
1 | 11 | 1 | 111 | 1 | 11
2 | 22 | 2 | 222 | 2 | 22
3 | | 3 | 333 | |
4 | 44 | 4 | | 4 | 44
5 | | | | |
(5 rows)
-- these should NOT give the same answers as above
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1) where (x2 is not null);
x1 | x2 | y1 | y2 | xx1 | xx2
----+----+----+-----+-----+-----
1 | 11 | 1 | 111 | 1 | 11
2 | 22 | 2 | 222 | 2 | 22
4 | 44 | 4 | | 4 | 44
(3 rows)
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1) where (y2 is not null);
x1 | x2 | y1 | y2 | xx1 | xx2
----+----+----+-----+-----+-----
1 | 11 | 1 | 111 | 1 | 11
2 | 22 | 2 | 222 | 2 | 22
3 | | 3 | 333 | 3 |
(3 rows)
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1) where (xx2 is not null);
x1 | x2 | y1 | y2 | xx1 | xx2
----+----+----+-----+-----+-----
1 | 11 | 1 | 111 | 1 | 11
2 | 22 | 2 | 222 | 2 | 22
4 | 44 | 4 | | 4 | 44
(3 rows)
--
-- Clean up
--

39
src/test/regress/sql/join.sql
Unescape View File

@ -292,6 +292,45 @@ NATURAL FULL JOIN
(SELECT name, n as s3_n FROM t3) as s3
) ss2;
-- Test for propagation of nullability constraints into sub-joins
create temp table x (x1 int, x2 int);
insert into x values (1,11);
insert into x values (2,22);
insert into x values (3,null);
insert into x values (4,44);
insert into x values (5,null);
create temp table y (y1 int, y2 int);
insert into y values (1,111);
insert into y values (2,222);
insert into y values (3,333);
insert into y values (4,null);
select * from x;
select * from y;
select * from x left join y on (x1 = y1 and x2 is not null);
select * from x left join y on (x1 = y1 and y2 is not null);
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1);
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1 and x2 is not null);
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1 and y2 is not null);
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1 and xx2 is not null);
-- these should NOT give the same answers as above
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1) where (x2 is not null);
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1) where (y2 is not null);
select * from (x left join y on (x1 = y1)) left join x xx(xx1,xx2)
on (x1 = xx1) where (xx2 is not null);
--
-- Clean up
--

Write Preview
Loading…
Cancel
Save