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Commit f0ac45bc authored by unknown's avatar unknown
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join_nested.test, join_nested.result: 

  Added a case for bug #4976 when one of the inner tables is empty.
select.result, join.result:
  Reversed the previous change of the erronious fix for bug #4976.
sql_select.cc:
  The previous fix for bug 4976 was reversed as it
  erroniously converted an outer join into an innner join
  when on_expression does not refer to outer tables.
  This is not valid if inner tables return an empty set.
  Setting dependency on outer tables was added for the above cases.
  To fix the crash in the test case of bug #4976  
  a guard was added that blocks running the crashing code for
  nested outer joins.


sql/sql_select.cc:
  The previous fix for bug 4976 was reversed as it
  erroniously converted an outer join into an innner join
  when on_expression does not refer to outer tables.
  This is not valid if inner tables return an empty set.
  Setting dependency on outer tables was added.
  The crash of the test case for bug #4976 was fixed
  adding a guard that blocks running the code for
  nested outer joins.
mysql-test/r/join.result:
  Reversed the previous change of the erronious fix for bug #4976.
mysql-test/r/select.result:
  Reversed the previous change of the erronious fix for bug #4976.
mysql-test/r/join_nested.result:
  Added a case for bug #4976 when one of the inner tables is empty.
mysql-test/t/join_nested.test:
  Added a case for bug #4976 when one of the inner tables is empty.
parent 4aa20acc
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Showing with 125 additions and 12 deletions
mysql-test/r/join.result
View file @ f0ac45bc
......@@ -59,9 +59,11 @@ id count(t2.id)
107 1
select t1.id,t2.id from t2 left join t1 on t1.id>=74 and t1.id<=0 where t2.id=75 and t1.id is null;
id id
NULL 75
explain select t1.id,t2.id from t2 left join t1 on t1.id>=74 and t1.id<=0 where t2.id=75 and t1.id is null;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
1 SIMPLE t1 const PRIMARY NULL NULL NULL 1 Impossible ON condition
1 SIMPLE t2 ALL NULL NULL NULL NULL 3 Using where
explain select t1.id, t2.id from t1, t2 where t2.id = t1.id and t1.id <0 and t1.id > 0;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
......
mysql-test/r/join_nested.result
View file @ f0ac45bc
......@@ -1218,12 +1218,106 @@ INSERT INTO t2 VALUES (NULL), (0), (1), (2), (3), (4), (5), (6), (7), (8), (9),
INSERT INTO t3 VALUES (0), (1), (2), (3), (4), (5);
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON c < 3 and b = c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 index c c 5 NULL 6 Using where; Using index
1 SIMPLE t2 ref b b 5 test.t3.c 2 Using where; Using index
1 SIMPLE t1 index NULL a 5 NULL 21 Using index
1 SIMPLE t3 index c c 5 NULL 6 Using index
1 SIMPLE t2 ref b b 5 test.t3.c 2 Using index
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range b b 5 NULL 3 Using where; Using index
1 SIMPLE t3 ref c c 5 test.t2.b 2 Using where; Using index
1 SIMPLE t1 index NULL a 5 NULL 21 Using index
1 SIMPLE t3 index c c 5 NULL 6 Using index
1 SIMPLE t2 ref b b 5 test.t3.c 2 Using index
SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
a b c
NULL 0 0
NULL 1 1
NULL 2 2
0 0 0
0 1 1
0 2 2
1 0 0
1 1 1
1 2 2
2 0 0
2 1 1
2 2 2
3 0 0
3 1 1
3 2 2
4 0 0
4 1 1
4 2 2
5 0 0
5 1 1
5 2 2
6 0 0
6 1 1
6 2 2
7 0 0
7 1 1
7 2 2
8 0 0
8 1 1
8 2 2
9 0 0
9 1 1
9 2 2
10 0 0
10 1 1
10 2 2
11 0 0
11 1 1
11 2 2
12 0 0
12 1 1
12 2 2
13 0 0
13 1 1
13 2 2
14 0 0
14 1 1
14 2 2
15 0 0
15 1 1
15 2 2
16 0 0
16 1 1
16 2 2
17 0 0
17 1 1
17 2 2
18 0 0
18 1 1
18 2 2
19 0 0
19 1 1
19 2 2
DELETE FROM t3;
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 5 NULL 21 Using index
1 SIMPLE t3 index c c 5 NULL 0 Using index
1 SIMPLE t2 ref b b 5 test.t3.c 2 Using index
SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
a b c
NULL NULL NULL
0 NULL NULL
1 NULL NULL
2 NULL NULL
3 NULL NULL
4 NULL NULL
5 NULL NULL
6 NULL NULL
7 NULL NULL
8 NULL NULL
9 NULL NULL
10 NULL NULL
11 NULL NULL
12 NULL NULL
13 NULL NULL
14 NULL NULL
15 NULL NULL
16 NULL NULL
17 NULL NULL
18 NULL NULL
19 NULL NULL
DROP TABLE t1,t2,t3;
mysql-test/r/select.result
View file @ f0ac45bc
......@@ -2181,10 +2181,10 @@ a a a
select * from (t1 as t2 left join t1 as t3 using (a)) left outer join t1 on t1.a>1;
a a a
1 1 2
2 2 2
3 3 2
1 1 3
2 2 2
2 2 3
3 3 2
3 3 3
select * from t1 left outer join (t1 as t2 left join t1 as t3 using (a)) on t1.a>1;
a a a
......
mysql-test/t/join_nested.test
View file @ f0ac45bc
......@@ -745,5 +745,10 @@ INSERT INTO t3 VALUES (0), (1), (2), (3), (4), (5);
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON c < 3 and b = c;
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
DELETE FROM t3;
EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
DROP TABLE t1,t2,t3;
sql/sql_select.cc
View file @ f0ac45bc
......@@ -2304,7 +2304,8 @@ make_join_statistics(JOIN *join,TABLE_LIST *tables,COND *conds,
if (s->worst_seeks < 2.0) // Fix for small tables
s->worst_seeks=2.0;
if (! s->const_keys.is_clear_all())
if (!s->const_keys.is_clear_all() &&
!s->table->pos_in_table_list->embedding)
{
ha_rows records;
SQL_SELECT *select;
......@@ -6077,10 +6078,8 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
table->embedding->nested_join->used_tables|= used_tables;
table->embedding->nested_join->not_null_tables|= not_null_tables;
}
if (!table->outer_join || (used_tables & not_null_tables) ||
(table->outer_join &&
!(table->on_expr->used_tables() & ~used_tables)))
if (!table->outer_join || (used_tables & not_null_tables))
{
/*
For some of the inner tables there are conjunctive predicates
......@@ -6130,7 +6129,20 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
if (prev_table->straight)
prev_table->dep_tables|= used_tables;
if (prev_table->on_expr)
{
prev_table->dep_tables|= table->on_expr_dep_tables;
table_map prev_used_tables= prev_table->nested_join ?
prev_table->nested_join->used_tables :
prev_table->table->map;
/*
If on expression contains only references to inner tables
we still make the inner tables dependent on the outer tables.
It would be enough to set dependency only on one outer table
for them. Yet this is really a rare case.
*/
if (!(prev_table->on_expr->used_tables() & ~prev_used_tables))
prev_table->dep_tables|= used_tables;
}
}
prev_table= table;
}
......
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