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Fix for bug#49199: Optimizer handles incorrectly:

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field='const1' AND field='const2' in some cases

Building multiple equality predicates containing
a constant which is compared as a datetime (with a field)
we should take this fact into account and compare the 
constant with another possible constatns as datetimes 
as well.

E.g. for the
SELECT ... WHERE a='2001-01-01' AND a='2001-01-01 00:00:00'
we should compare '2001-01-01' with '2001-01-01 00:00:00' as
datetimes but not as strings.
This commit is contained in:
Ramil Kalimullin 2009-12-04 21:58:40 +04:00
parent eb9114229f
commit 7888c98327
5 changed files with 178 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

84
mysql-test/r/select.result
View file

@ -4456,4 +4456,88 @@ SELECT 1 FROM t2 JOIN t1 ON 1=1
WHERE a != '1' AND NOT a >= b OR NOT ROW(b,a )<> ROW(a,a);
1
DROP TABLE t1,t2;
#
# Bug #49199: Optimizer handles incorrectly:
# field='const1' AND field='const2' in some cases
CREATE TABLE t1(a DATETIME NOT NULL);
INSERT INTO t1 VALUES('2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
a
2001-01-01 00:00:00
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1
Warnings:
Note 1003 select '2001-01-01 00:00:00' AS `a` from `test`.`t1` where 1
DROP TABLE t1;
CREATE TABLE t1(a DATE NOT NULL);
INSERT INTO t1 VALUES('2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
a
2001-01-01
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1
Warnings:
Note 1003 select '2001-01-01' AS `a` from `test`.`t1` where 1
DROP TABLE t1;
CREATE TABLE t1(a TIMESTAMP NOT NULL);
INSERT INTO t1 VALUES('2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
a
2001-01-01 00:00:00
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1
Warnings:
Note 1003 select '2001-01-01 00:00:00' AS `a` from `test`.`t1` where 1
DROP TABLE t1;
CREATE TABLE t1(a DATETIME NOT NULL, b DATE NOT NULL);
INSERT INTO t1 VALUES('2001-01-01', '2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
a b
2001-01-01 00:00:00 2001-01-01
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1
Warnings:
Note 1003 select '2001-01-01 00:00:00' AS `a`,'2001-01-01' AS `b` from `test`.`t1` where 1
DROP TABLE t1;
CREATE TABLE t1(a DATETIME NOT NULL, b VARCHAR(20) NOT NULL);
INSERT INTO t1 VALUES('2001-01-01', '2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
a b
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
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
Warnings:
Note 1003 select '2001-01-01 00:00:00' AS `a`,'2001-01-01' AS `b` from `test`.`t1` where 0
SELECT * FROM t1 WHERE a='2001-01-01 00:00:00' AND a=b AND b='2001-01-01';
a b
2001-01-01 00:00:00 2001-01-01
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01 00:00:00' AND a=b AND b='2001-01-01';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1
Warnings:
Note 1003 select '2001-01-01 00:00:00' AS `a`,'2001-01-01' AS `b` from `test`.`t1` where 1
DROP TABLE t1;
CREATE TABLE t1(a DATETIME NOT NULL, b DATE NOT NULL);
INSERT INTO t1 VALUES('2001-01-01', '2001-01-01');
SELECT x.a, y.a, z.a FROM t1 x
JOIN t1 y ON x.a=y.a
JOIN t1 z ON y.a=z.a
WHERE x.a='2001-01-01' AND z.a='2001-01-01 00:00:00';
a a a
2001-01-01 00:00:00 2001-01-01 00:00:00 2001-01-01 00:00:00
EXPLAIN EXTENDED SELECT x.a, y.a, z.a FROM t1 x
JOIN t1 y ON x.a=y.a
JOIN t1 z ON y.a=z.a
WHERE x.a='2001-01-01' AND z.a='2001-01-01 00:00:00';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE x system NULL NULL NULL NULL 1
1 SIMPLE y system NULL NULL NULL NULL 1
1 SIMPLE z system NULL NULL NULL NULL 1
Warnings:
Note 1003 select '2001-01-01 00:00:00' AS `a`,'2001-01-01 00:00:00' AS `a`,'2001-01-01 00:00:00' AS `a` from `test`.`t1` `x` join `test`.`t1` `y` join `test`.`t1` `z` where 1
End of 5.0 tests

49
mysql-test/t/select.test
View file

@ -3797,4 +3797,53 @@ SELECT 1 FROM t2 JOIN t1 ON 1=1
DROP TABLE t1,t2;
--echo #
--echo # Bug #49199: Optimizer handles incorrectly:
--echo # field='const1' AND field='const2' in some cases
--echo
CREATE TABLE t1(a DATETIME NOT NULL);
INSERT INTO t1 VALUES('2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
DROP TABLE t1;
CREATE TABLE t1(a DATE NOT NULL);
INSERT INTO t1 VALUES('2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
DROP TABLE t1;
CREATE TABLE t1(a TIMESTAMP NOT NULL);
INSERT INTO t1 VALUES('2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a='2001-01-01 00:00:00';
DROP TABLE t1;
CREATE TABLE t1(a DATETIME NOT NULL, b DATE NOT NULL);
INSERT INTO t1 VALUES('2001-01-01', '2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
DROP TABLE t1;
CREATE TABLE t1(a DATETIME NOT NULL, b VARCHAR(20) NOT NULL);
INSERT INTO t1 VALUES('2001-01-01', '2001-01-01');
SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01' AND a=b AND b='2001-01-01 00:00:00';
SELECT * FROM t1 WHERE a='2001-01-01 00:00:00' AND a=b AND b='2001-01-01';
EXPLAIN EXTENDED SELECT * FROM t1 WHERE a='2001-01-01 00:00:00' AND a=b AND b='2001-01-01';
DROP TABLE t1;
CREATE TABLE t1(a DATETIME NOT NULL, b DATE NOT NULL);
INSERT INTO t1 VALUES('2001-01-01', '2001-01-01');
SELECT x.a, y.a, z.a FROM t1 x
JOIN t1 y ON x.a=y.a
JOIN t1 z ON y.a=z.a
WHERE x.a='2001-01-01' AND z.a='2001-01-01 00:00:00';
EXPLAIN EXTENDED SELECT x.a, y.a, z.a FROM t1 x
JOIN t1 y ON x.a=y.a
JOIN t1 z ON y.a=z.a
WHERE x.a='2001-01-01' AND z.a='2001-01-01 00:00:00';
--echo End of 5.0 tests

46
sql/item_cmpfunc.cc
View file

@ -4903,7 +4903,8 @@ Item *Item_bool_rowready_func2::negated_item()
}
Item_equal::Item_equal(Item_field *f1, Item_field *f2)
: Item_bool_func(), const_item(0), eval_item(0), cond_false(0)
: Item_bool_func(), const_item(0), eval_item(0), cond_false(0),
compare_as_dates(FALSE)
{
const_item_cache= 0;
fields.push_back(f1);
@ -4916,6 +4917,7 @@ Item_equal::Item_equal(Item *c, Item_field *f)
const_item_cache= 0;
fields.push_back(f);
const_item= c;
compare_as_dates= f->is_datetime();
}
@ -4930,9 +4932,45 @@ Item_equal::Item_equal(Item_equal *item_equal)
fields.push_back(item);
}
const_item= item_equal->const_item;
compare_as_dates= item_equal->compare_as_dates;
cond_false= item_equal->cond_false;
}
void Item_equal::compare_const(Item *c)
{
if (compare_as_dates)
{
cmp.set_datetime_cmp_func(&c, &const_item);
cond_false= cmp.compare();
}
else
{
Item_func_eq *func= new Item_func_eq(c, const_item);
func->set_cmp_func();
func->quick_fix_field();
cond_false= !func->val_int();
}
if (cond_false)
const_item_cache= 1;
}
void Item_equal::add(Item *c, Item_field *f)
{
if (cond_false)
return;
if (!const_item)
{
DBUG_ASSERT(f);
const_item= c;
compare_as_dates= f->is_datetime();
return;
}
compare_const(c);
}
void Item_equal::add(Item *c)
{
if (cond_false)
@ -4942,11 +4980,7 @@ void Item_equal::add(Item *c)
const_item= c;
return;
}
Item_func_eq *func= new Item_func_eq(c, const_item);
func->set_cmp_func();
func->quick_fix_field();
if ((cond_false= !func->val_int()))
const_item_cache= 1;
compare_const(c);
}
void Item_equal::add(Item_field *f)

4
sql/item_cmpfunc.h
View file

@ -1477,7 +1477,9 @@ class Item_equal: public Item_bool_func
List<Item_field> fields; /* list of equal field items */
Item *const_item; /* optional constant item equal to fields items */
cmp_item *eval_item;
Arg_comparator cmp;
bool cond_false;
bool compare_as_dates;
public:
inline Item_equal()
: Item_bool_func(), const_item(0), eval_item(0), cond_false(0)
@ -1486,6 +1488,8 @@ public:
Item_equal(Item *c, Item_field *f);
Item_equal(Item_equal *item_equal);
inline Item* get_const() { return const_item; }
void compare_const(Item *c);
void add(Item *c, Item_field *f);
void add(Item *c);
void add(Item_field *f);
uint members();

2
sql/sql_select.cc
View file

@ -7237,7 +7237,7 @@ static bool check_simple_equality(Item *left_item, Item *right_item,
already contains a constant and its value is not equal to
the value of const_item.
*/
item_equal->add(const_item);
item_equal->add(const_item, field_item);
}
else
{