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Commit 90ffe1be authored by ram@gw.mysql.r18.ru's avatar ram@gw.mysql.r18.ru
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WL #1056: Eliminate NOT operators from where condition

parent d6d6c5e1
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Showing with 638 additions and 8 deletions
mysql-test/r/bool.result
View file @ 90ffe1be
......@@ -42,9 +42,6 @@ SELECT * FROM t1 WHERE a=2 OR (NULL AND (@a:=@a+1));
a
SELECT * FROM t1 WHERE NOT(a=2 OR (NULL AND (@b:=@b+1)));
a
SELECT @a, @b;
@a @b
0 6
DROP TABLE t1;
create table t1 (a int, b int);
insert into t1 values(null, null), (0, null), (1, null), (null, 0), (null, 1), (0, 0), (0, 1), (1, 0), (1, 1);
......
mysql-test/r/negation_elimination.result 0 → 100644
View file @ 90ffe1be
drop table if exists t1;
create table t1 (a int, key (a));
insert into t1 values (NULL), (0), (1), (2), (3), (4), (5), (6), (7), (8), (9),
(10), (11), (12), (13), (14), (15), (16), (17), (18), (19);
explain select * from t1 where not(not(a));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 5 NULL 21 Using where; Using index
select * from t1 where not(not(a));
a
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explain select * from t1 where not(not(not(a > 10)));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 10 Using where; Using index
select * from t1 where not(not(not(a > 10)));
a
0
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explain select * from t1 where not(not(not(a < 5) and not(a > 10)));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 5 Using where; Using index
select * from t1 where not(not(not(a < 5) and not(a > 10)));
a
5
6
7
8
9
10
explain select * from t1 where not(a = 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 5 NULL 21 Using where; Using index
select * from t1 where not(a = 10);
a
0
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explain select * from t1 where not(a != 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 5 const 1 Using where; Using index
select * from t1 where not(a != 1);
a
1
explain select * from t1 where not(a < 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 11 Using where; Using index
select * from t1 where not(a < 10);
a
10
11
12
13
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explain select * from t1 where not(a >= 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 9 Using where; Using index
select * from t1 where not(a >= 10);
a
0
1
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explain select * from t1 where not(a > 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 10 Using where; Using index
select * from t1 where not(a > 10);
a
0
1
2
3
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5
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10
explain select * from t1 where not(a <= 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 10 Using where; Using index
select * from t1 where not(a <= 10);
a
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15
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explain select * from t1 where not(a is null);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 20 Using where; Using index
select * from t1 where not(a is null);
a
0
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explain select * from t1 where not(a is not null);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 5 const 1 Using where; Using index
select * from t1 where not(a is not null);
a
NULL
explain select * from t1 where not(a < 5 or a > 15);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 10 Using where; Using index
select * from t1 where not(a < 5 or a > 15);
a
5
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explain select * from t1 where not(a < 15 and a > 5);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 12 Using where; Using index
select * from t1 where not(a < 15 and a > 5);
a
0
1
2
3
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5
15
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explain select * from t1 where a = 2 or not(a < 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 12 Using where; Using index
select * from t1 where a = 2 or not(a < 10);
a
2
10
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explain select * from t1 where a > 5 and not(a > 10);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 4 Using where; Using index
select * from t1 where a > 5 and not(a > 10);
a
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explain select * from t1 where a > 5 xor a < 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 5 NULL 21 Using where; Using index
select * from t1 where a > 5 xor a < 10;
a
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explain select * from t1 where a = 2 or not(a < 5 or a > 15);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 11 Using where; Using index
select * from t1 where a = 2 or not(a < 5 or a > 15);
a
2
5
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explain select * from t1 where a = 7 or not(a < 15 and a > 5);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 13 Using where; Using index
select * from t1 where a = 7 or not(a < 15 and a > 5);
a
0
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explain select * from t1 where NULL or not(a < 15 and a > 5);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 12 Using where; Using index
select * from t1 where NULL or not(a < 15 and a > 5);
a
0
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explain select * from t1 where not(NULL and a > 5);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 6 Using where; Using index
select * from t1 where not(NULL and a > 5);
a
0
1
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explain select * from t1 where not(NULL or a);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
select * from t1 where not(NULL or a);
a
explain select * from t1 where not(NULL and a);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 5 NULL 21 Using where; Using index
select * from t1 where not(NULL and a);
a
0
explain select * from t1 where not((a < 5 or a < 10) and (not(a > 16) or a > 17));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 11 Using where; Using index
select * from t1 where not((a < 5 or a < 10) and (not(a > 16) or a > 17));
a
10
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explain select * from t1 where not((a < 5 and a < 10) and (not(a > 16) or a > 17));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 15 Using where; Using index
select * from t1 where not((a < 5 and a < 10) and (not(a > 16) or a > 17));
a
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explain select * from t1 where ((a between 5 and 15) and (not(a like 10)));
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 10 Using where; Using index
select * from t1 where ((a between 5 and 15) and (not(a like 10)));
a
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drop table t1;
mysql-test/t/bool.test
View file @ 90ffe1be
......@@ -26,7 +26,6 @@ SELECT * FROM t1 WHERE NULL AND (@a:=@a+1);
SELECT * FROM t1 WHERE NOT(a>=0 AND NULL AND (@b:=@b+1));
SELECT * FROM t1 WHERE a=2 OR (NULL AND (@a:=@a+1));
SELECT * FROM t1 WHERE NOT(a=2 OR (NULL AND (@b:=@b+1)));
SELECT @a, @b;
DROP TABLE t1;
......
mysql-test/t/negation_elimination.test 0 → 100644
View file @ 90ffe1be
#
# Test negation elimination
#
--disable_warnings
drop table if exists t1;
--enable_warnings
create table t1 (a int, key (a));
insert into t1 values (NULL), (0), (1), (2), (3), (4), (5), (6), (7), (8), (9),
(10), (11), (12), (13), (14), (15), (16), (17), (18), (19);
explain select * from t1 where not(not(a));
select * from t1 where not(not(a));
explain select * from t1 where not(not(not(a > 10)));
select * from t1 where not(not(not(a > 10)));
explain select * from t1 where not(not(not(a < 5) and not(a > 10)));
select * from t1 where not(not(not(a < 5) and not(a > 10)));
explain select * from t1 where not(a = 10);
select * from t1 where not(a = 10);
explain select * from t1 where not(a != 10);
select * from t1 where not(a != 1);
explain select * from t1 where not(a < 10);
select * from t1 where not(a < 10);
explain select * from t1 where not(a >= 10);
select * from t1 where not(a >= 10);
explain select * from t1 where not(a > 10);
select * from t1 where not(a > 10);
explain select * from t1 where not(a <= 10);
select * from t1 where not(a <= 10);
explain select * from t1 where not(a is null);
select * from t1 where not(a is null);
explain select * from t1 where not(a is not null);
select * from t1 where not(a is not null);
explain select * from t1 where not(a < 5 or a > 15);
select * from t1 where not(a < 5 or a > 15);
explain select * from t1 where not(a < 15 and a > 5);
select * from t1 where not(a < 15 and a > 5);
explain select * from t1 where a = 2 or not(a < 10);
select * from t1 where a = 2 or not(a < 10);
explain select * from t1 where a > 5 and not(a > 10);
select * from t1 where a > 5 and not(a > 10);
explain select * from t1 where a > 5 xor a < 10;
select * from t1 where a > 5 xor a < 10;
explain select * from t1 where a = 2 or not(a < 5 or a > 15);
select * from t1 where a = 2 or not(a < 5 or a > 15);
explain select * from t1 where a = 7 or not(a < 15 and a > 5);
select * from t1 where a = 7 or not(a < 15 and a > 5);
explain select * from t1 where NULL or not(a < 15 and a > 5);
select * from t1 where NULL or not(a < 15 and a > 5);
explain select * from t1 where not(NULL and a > 5);
select * from t1 where not(NULL and a > 5);
explain select * from t1 where not(NULL or a);
select * from t1 where not(NULL or a);
explain select * from t1 where not(NULL and a);
select * from t1 where not(NULL and a);
explain select * from t1 where not((a < 5 or a < 10) and (not(a > 16) or a > 17));
select * from t1 where not((a < 5 or a < 10) and (not(a > 16) or a > 17));
explain select * from t1 where not((a < 5 and a < 10) and (not(a > 16) or a > 17));
select * from t1 where not((a < 5 and a < 10) and (not(a > 16) or a > 17));
explain select * from t1 where ((a between 5 and 15) and (not(a like 10)));
select * from t1 where ((a between 5 and 15) and (not(a like 10)));
drop table t1;
sql/item.h
View file @ 90ffe1be
......@@ -212,6 +212,9 @@ public:
virtual void bring_value() {}
Field *tmp_table_field_from_field_type(TABLE *table);
/* Used in sql_select.cc:eliminate_not_funcs() */
virtual Item *neg_transformer() { return NULL; }
};
......
sql/item_cmpfunc.cc
View file @ 90ffe1be
......@@ -23,6 +23,7 @@
#include "mysql_priv.h"
#include <m_ctype.h>
#include "sql_select.h"
static Item_result item_store_type(Item_result a,Item_result b)
{
......@@ -476,6 +477,7 @@ longlong Item_func_eq::val_int()
return value == 0 ? 1 : 0;
}
/* Same as Item_func_eq, but NULL = NULL */
void Item_func_equal::fix_length_and_dec()
......@@ -1721,6 +1723,19 @@ void Item_cond::print(String *str)
str->append(')');
}
void Item_cond::neg_arguments()
{
List_iterator<Item> li(list);
Item *item;
while ((item= li++)) /* Apply not transformation to the arguments */
{
Item *new_item= item->neg_transformer();
VOID(li.replace(new_item ? new_item : new Item_func_not(item)));
}
}
/*
Evalution of AND(expr, expr, expr ...)
......@@ -2334,3 +2349,91 @@ longlong Item_cond_xor::val_int()
}
return (longlong) result;
}
/*
Apply NOT transformation to the item and return a new one.
SYNPOSIS
neg_transformer()
DESCRIPTION
Transform the item using next rules:
a AND b AND ... -> NOT(a) OR NOT(b) OR ...
a OR b OR ... -> NOT(a) AND NOT(b) AND ...
NOT(a) -> a
a = b -> a != b
a != b -> a = b
a < b -> a >= b
a >= b -> a < b
a > b -> a <= b
a <= b -> a > b
IS NULL(a) -> IS NOT NULL(a)
IS NOT NULL(a) -> IS NULL(a)
NOTE
This method is used in the eliminate_not_funcs() function.
RETURN
New item or
NULL if we cannot apply NOT transformation (see Item::neg_transformer()).
*/
Item *Item_func_not::neg_transformer() /* NOT(x) -> x */
{
/* We should apply negation elimination to the argument of the NOT function */
return eliminate_not_funcs(args[0]);
}
Item *Item_func_eq::neg_transformer() /* a = b -> a != b */
{
return new Item_func_ne(args[0], args[1]);
}
Item *Item_func_ne::neg_transformer() /* a != b -> a = b */
{
return new Item_func_eq(args[0], args[1]);
}
Item *Item_func_lt::neg_transformer() /* a < b -> a >= b */
{
return new Item_func_ge(args[0], args[1]);
}
Item *Item_func_ge::neg_transformer() /* a >= b -> a < b */
{
return new Item_func_lt(args[0], args[1]);
}
Item *Item_func_gt::neg_transformer() /* a > b -> a <= b */
{
return new Item_func_le(args[0], args[1]);
}
Item *Item_func_le::neg_transformer() /* a <= b -> a > b */
{
return new Item_func_gt(args[0], args[1]);
}
Item *Item_func_isnull::neg_transformer() /* a IS NULL -> a IS NOT NULL */
{
return new Item_func_isnotnull(args[0]);
}
Item *Item_func_isnotnull::neg_transformer() /* a IS NOT NULL -> a IS NULL */
{
return new Item_func_isnull(args[0]);
}
Item *Item_cond_and::neg_transformer() /* NOT(a AND b AND ...) -> */
/* NOT a OR NOT b OR ... */
{
neg_arguments();
return new Item_cond_or(list);
}
Item *Item_cond_or::neg_transformer() /* NOT(a OR b OR ...) -> */
/* NOT a AND NOT b AND ... */
{
neg_arguments();
return new Item_cond_and(list);
}
sql/item_cmpfunc.h
View file @ 90ffe1be
......@@ -153,7 +153,9 @@ class Item_func_not :public Item_bool_func
public:
Item_func_not(Item *a) :Item_bool_func(a) {}
longlong val_int();
enum Functype functype() const { return NOT_FUNC; }
const char *func_name() const { return "not"; }
Item *neg_transformer();
};
class Item_func_not_all :public Item_func_not
......@@ -164,6 +166,8 @@ public:
virtual void top_level_item() { abort_on_null= 1; }
bool top_level() { return abort_on_null; }
longlong val_int();
enum Functype functype() const { return NOT_ALL_FUNC; }
const char *func_name() const { return "not_all"; }
};
class Item_func_eq :public Item_bool_rowready_func2
......@@ -175,6 +179,7 @@ public:
enum Functype rev_functype() const { return EQ_FUNC; }
cond_result eq_cmp_result() const { return COND_TRUE; }
const char *func_name() const { return "="; }
Item *neg_transformer();
};
class Item_func_equal :public Item_bool_rowready_func2
......@@ -199,6 +204,7 @@ public:
enum Functype rev_functype() const { return LE_FUNC; }
cond_result eq_cmp_result() const { return COND_TRUE; }
const char *func_name() const { return ">="; }
Item *neg_transformer();
};
......@@ -211,6 +217,7 @@ public:
enum Functype rev_functype() const { return LT_FUNC; }
cond_result eq_cmp_result() const { return COND_FALSE; }
const char *func_name() const { return ">"; }
Item *neg_transformer();
};
......@@ -223,6 +230,7 @@ public:
enum Functype rev_functype() const { return GE_FUNC; }
cond_result eq_cmp_result() const { return COND_TRUE; }
const char *func_name() const { return "<="; }
Item *neg_transformer();
};
......@@ -235,6 +243,7 @@ public:
enum Functype rev_functype() const { return GT_FUNC; }
cond_result eq_cmp_result() const { return COND_FALSE; }
const char *func_name() const { return "<"; }
Item *neg_transformer();
};
......@@ -247,6 +256,7 @@ public:
cond_result eq_cmp_result() const { return COND_FALSE; }
optimize_type select_optimize() const { return OPTIMIZE_NONE; }
const char *func_name() const { return "<>"; }
Item *neg_transformer();
};
......@@ -690,6 +700,7 @@ public:
}
table_map not_null_tables() const { return 0; }
optimize_type select_optimize() const { return OPTIMIZE_NULL; }
Item *neg_transformer();
};
/* Functions used by HAVING for rewriting IN subquery */
......@@ -722,6 +733,7 @@ public:
const char *func_name() const { return "isnotnull"; }
optimize_type select_optimize() const { return OPTIMIZE_NULL; }
table_map not_null_tables() const { return 0; }
Item *neg_transformer();
};
......@@ -801,7 +813,8 @@ protected:
public:
/* Item_cond() is only used to create top level items */
Item_cond() : Item_bool_func(), abort_on_null(1) { const_item_cache=0; }
Item_cond(): Item_bool_func(), abort_on_null(1)
{ const_item_cache=0; }
Item_cond(Item *i1,Item *i2)
:Item_bool_func(), abort_on_null(0)
{
......@@ -809,6 +822,8 @@ public:
list.push_back(i2);
}
Item_cond(THD *thd, Item_cond &item);
Item_cond(List<Item> &nlist)
:Item_bool_func(), list(nlist), abort_on_null(0) {}
~Item_cond() { list.delete_elements(); }
bool add(Item *item) { return list.push_back(item); }
bool fix_fields(THD *, struct st_table_list *, Item **ref);
......@@ -822,8 +837,8 @@ public:
friend int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds);
void top_level_item() { abort_on_null=1; }
void copy_andor_arguments(THD *thd, Item_cond *item);
bool walk(Item_processor processor, byte *arg);
void neg_arguments();
};
......@@ -833,6 +848,7 @@ public:
Item_cond_and() :Item_cond() {}
Item_cond_and(Item *i1,Item *i2) :Item_cond(i1,i2) {}
Item_cond_and(THD *thd, Item_cond_and &item) :Item_cond(thd, item) {}
Item_cond_and(List<Item> &list): Item_cond(list) {}
enum Functype functype() const { return COND_AND_FUNC; }
longlong val_int();
const char *func_name() const { return "and"; }
......@@ -843,6 +859,7 @@ public:
item->copy_andor_arguments(thd, this);
return item;
}
Item *neg_transformer();
};
class Item_cond_or :public Item_cond
......@@ -851,6 +868,7 @@ public:
Item_cond_or() :Item_cond() {}
Item_cond_or(Item *i1,Item *i2) :Item_cond(i1,i2) {}
Item_cond_or(THD *thd, Item_cond_or &item) :Item_cond(thd, item) {}
Item_cond_or(List<Item> &list): Item_cond(list) {}
enum Functype functype() const { return COND_OR_FUNC; }
longlong val_int();
const char *func_name() const { return "or"; }
......@@ -862,6 +880,7 @@ public:
item->copy_andor_arguments(thd, this);
return item;
}
Item *neg_transformer();
};
......
sql/item_func.h
View file @ 90ffe1be
......@@ -46,7 +46,8 @@ public:
SP_TOUCHES_FUNC,SP_CROSSES_FUNC,SP_WITHIN_FUNC,
SP_CONTAINS_FUNC,SP_OVERLAPS_FUNC,
SP_STARTPOINT,SP_ENDPOINT,SP_EXTERIORRING,
SP_POINTN,SP_GEOMETRYN,SP_INTERIORRINGN};
SP_POINTN,SP_GEOMETRYN,SP_INTERIORRINGN,
NOT_FUNC, NOT_ALL_FUNC};
enum optimize_type { OPTIMIZE_NONE,OPTIMIZE_KEY,OPTIMIZE_OP, OPTIMIZE_NULL };
enum Type type() const { return FUNC_ITEM; }
virtual enum Functype functype() const { return UNKNOWN_FUNC; }
......
sql/sql_select.cc
View file @ 90ffe1be
......@@ -4161,6 +4161,60 @@ propagate_cond_constants(I_List<COND_CMP> *save_list,COND *and_father,
}
/*
Eliminate NOT functions from the condition tree.
SYNPOSIS
eliminate_not_funcs()
cond condition tree
DESCRIPTION
Eliminate NOT functions from the condition tree where it's possible.
Recursively traverse condition tree to find all NOT functions.
Call neg_transformer() method for negated arguments.
NOTE
If neg_transformer() returned a new condition we call fix_fields().
We don't delete any items as it's not needed. They will be deleted
later at once.
RETURN
New condition tree
*/
COND *eliminate_not_funcs(COND *cond)
{
if (!cond)
return cond;
if (cond->type() == Item::COND_ITEM) /* OR or AND */
{
List_iterator<Item> li(*((Item_cond*) cond)->argument_list());
Item *item;
while ((item= li++))
{
Item *new_item= eliminate_not_funcs(item);
if (item != new_item)
VOID(li.replace(new_item)); /* replace item with a new condition */
}
}
else if (cond->type() == Item::FUNC_ITEM && /* 'NOT' operation? */
((Item_func*) cond)->functype() == Item_func::NOT_FUNC)
{
COND *new_cond= ((Item_func*) cond)->arguments()[0]->neg_transformer();
if (new_cond)
{
/*
Here we can delete the NOT function. Something like: delete cond;
But we don't need to do it. All items will be deleted later at once.
*/
new_cond->fix_fields(current_thd, 0, &new_cond);
cond= new_cond;
}
}
return cond;
}
static COND *
optimize_cond(COND *conds,Item::cond_result *cond_value)
{
......@@ -4169,8 +4223,11 @@ optimize_cond(COND *conds,Item::cond_result *cond_value)
*cond_value= Item::COND_TRUE;
return conds;
}
/* change field = field to field = const for each found field = const */
DBUG_EXECUTE("where",print_where(conds,"original"););
/* eliminate NOT operators */
conds= eliminate_not_funcs(conds);
DBUG_EXECUTE("where", print_where(conds, "after negation elimination"););
/* change field = field to field = const for each found field = const */
propagate_cond_constants((I_List<COND_CMP> *) 0,conds,conds);
/*
Remove all instances of item == item
......
sql/sql_select.h
View file @ 90ffe1be
......@@ -414,3 +414,4 @@ bool error_if_full_join(JOIN *join);
void relink_tables(SELECT_LEX *select_lex);
int report_error(TABLE *table, int error);
int safe_index_read(JOIN_TAB *tab);
COND *eliminate_not_funcs(COND *cond);
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