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Merge in fix for BUG#727667

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This commit is contained in:
Sergey Petrunya
2011-03-25 12:47:44 +03:00
parent ec23949158 0fe8c972c6
commit 201fb06db9
11 changed files with 109 additions and 22 deletions
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2
mysql-test/r/null.result
View File

@@ -170,7 +170,7 @@ insert into t1 select i*2 from t1;
insert into t1 values(null); insert into t1 values(null);
explain select * from t1 where i=2 or i is null; explain select * from t1 where i=2 or i is null;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null i i 5 const 9 Using index 1 SIMPLE t1 ref_or_null i i 5 const 9 Using where; Using index
select count(*) from t1 where i=2 or i is null; select count(*) from t1 where i=2 or i is null;
count(*) count(*)
10 10

26
mysql-test/r/null_key.result
View File

@@ -21,10 +21,10 @@ id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a,b a 9 NULL 3 Using where; Using index 1 SIMPLE t1 range a,b a 9 NULL 3 Using where; Using index
explain select * from t1 where (a is null or a = 7) and b=7; explain select * from t1 where (a is null or a = 7) and b=7;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null a,b a 9 const,const 2 Using index 1 SIMPLE t1 ref_or_null a,b a 9 const,const 2 Using where; Using index
explain select * from t1 where (a is null or a = 7) and b=7 order by a; explain select * from t1 where (a is null or a = 7) and b=7 order by a;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null a,b a 9 const,const 2 Using index; Using filesort 1 SIMPLE t1 ref_or_null a,b a 9 const,const 2 Using where; Using index; Using filesort
explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2; explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a,b a 5 const 3 Using where; Using index 1 SIMPLE t1 ref a,b a 5 const 3 Using where; Using index
@@ -151,7 +151,7 @@ alter table t1 modify b int null;
insert into t1 values (7,null), (8,null), (8,7); insert into t1 values (7,null), (8,null), (8,7);
explain select * from t1 where a = 7 and (b=7 or b is null); explain select * from t1 where a = 7 and (b=7 or b is null);
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null a,b a 10 const,const 2 Using index 1 SIMPLE t1 ref_or_null a,b a 10 const,const 2 Using where; Using index
select * from t1 where a = 7 and (b=7 or b is null); select * from t1 where a = 7 and (b=7 or b is null);
a b a b
7 7 7 7
@@ -166,7 +166,7 @@ a b
NULL 7 NULL 7
explain select * from t1 where (a = 7 or a is null) and (a = 7 or a is null); explain select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null a a 5 const 5 Using index 1 SIMPLE t1 ref_or_null a a 5 const 5 Using where; Using index
select * from t1 where (a = 7 or a is null) and (a = 7 or a is null); select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
a b a b
7 NULL 7 NULL
@@ -192,7 +192,7 @@ a a b
explain select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null); explain select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 2 Using where 1 SIMPLE t2 ALL NULL NULL NULL NULL 2 Using where
1 SIMPLE t1 ref_or_null a a 10 test.t2.a,const 4 Using index 1 SIMPLE t1 ref_or_null a a 10 test.t2.a,const 4 Using where; Using index
select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null); select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
a a b a a b
7 7 7 7 7 7
@@ -202,7 +202,7 @@ a a b
explain select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7; explain select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 2 1 SIMPLE t2 ALL NULL NULL NULL NULL 2
1 SIMPLE t1 ref_or_null a a 10 test.t2.a,const 4 Using index 1 SIMPLE t1 ref_or_null a a 10 test.t2.a,const 4 Using where; Using index
select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7; select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
a a b a a b
7 7 7 7 7 7
@@ -226,7 +226,7 @@ delete from t1 where a=8;
explain select * from t2,t1 where t1.a=t2.a or t1.a is null; explain select * from t2,t1 where t1.a=t2.a or t1.a is null;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 4 1 SIMPLE t2 ALL NULL NULL NULL NULL 4
1 SIMPLE t1 ref_or_null a a 5 test.t2.a 4 Using index 1 SIMPLE t1 ref_or_null a a 5 test.t2.a 4 Using where; Using index
explain select * from t2,t1 where t1.a<=>t2.a or (t1.a is null and t1.b <> 9); explain select * from t2,t1 where t1.a<=>t2.a or (t1.a is null and t1.b <> 9);
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 4 1 SIMPLE t2 ALL NULL NULL NULL NULL 4
@@ -447,3 +447,15 @@ a b a b
3 12 0 12 3 12 0 12
drop table t1, t2; drop table t1, t2;
End of 5.0 tests End of 5.0 tests
#
# BUG#727667 Wrong result with OR + NOT NULL in maria-5.3
#
CREATE TABLE t1 (
f3 int(11),
f10 varchar(1),
KEY (f3)
);
INSERT INTO t1 VALUES ('9','k'),(NULL,'r');
SELECT * FROM t1 WHERE (f3 = 83) OR (f10 = 'z' AND f3 IS NULL);
f3 f10
DROP TABLE t1;

4
mysql-test/r/order_by.result
View File

@@ -643,7 +643,7 @@ create table t1(a int, b int, index(b));
insert into t1 values (2, 1), (1, 1), (4, NULL), (3, NULL), (6, 2), (5, 2); insert into t1 values (2, 1), (1, 1), (4, NULL), (3, NULL), (6, 2), (5, 2);
explain select * from t1 where b=1 or b is null order by a; explain select * from t1 where b=1 or b is null order by a;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null b b 5 const 3 Using filesort 1 SIMPLE t1 ref_or_null b b 5 const 3 Using index condition; Using filesort
select * from t1 where b=1 or b is null order by a; select * from t1 where b=1 or b is null order by a;
a b a b
1 1 1 1
@@ -652,7 +652,7 @@ a b
4 NULL 4 NULL
explain select * from t1 where b=2 or b is null order by a; explain select * from t1 where b=2 or b is null order by a;
id select_type table type possible_keys key key_len ref rows Extra id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null b b 5 const 4 Using filesort 1 SIMPLE t1 ref_or_null b b 5 const 4 Using index condition; Using filesort
select * from t1 where b=2 or b is null order by a; select * from t1 where b=2 or b is null order by a;
a b a b
3 NULL 3 NULL

2
mysql-test/r/subselect.result
View File

@@ -906,7 +906,7 @@ a t1.a in (select t2.a from t2,t3 where t3.a=t2.a)
explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1; explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
id select_type table type possible_keys key key_len ref rows filtered Extra id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index 1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index
2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using index 2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join) 2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join)
Warnings: Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1` Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`

2
mysql-test/r/subselect_no_mat.result
View File

@@ -910,7 +910,7 @@ a t1.a in (select t2.a from t2,t3 where t3.a=t2.a)
explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1; explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
id select_type table type possible_keys key key_len ref rows filtered Extra id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index 1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index
2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using index 2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join) 2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join)
Warnings: Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1` Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`

2
mysql-test/r/subselect_no_opts.result
View File

@@ -907,7 +907,7 @@ a t1.a in (select t2.a from t2,t3 where t3.a=t2.a)
explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1; explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
id select_type table type possible_keys key key_len ref rows filtered Extra id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index 1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index
2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using index 2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join) 2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join)
Warnings: Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1` Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`

2
mysql-test/r/subselect_no_semijoin.result
View File

@@ -907,7 +907,7 @@ a t1.a in (select t2.a from t2,t3 where t3.a=t2.a)
explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1; explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
id select_type table type possible_keys key key_len ref rows filtered Extra id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index 1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index
2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using index 2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 100.00 Using where; Using index
2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join) 2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 100.00 Using where; Using join buffer (flat, BNL join)
Warnings: Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1` Note 1003 select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`

13
mysql-test/t/null_key.test
View File

@@ -263,3 +263,16 @@ SELECT * FROM t2 inner join t1 WHERE ( t1.a = 0 OR t1.a IS NULL) AND t2.a = 3 AN
drop table t1, t2; drop table t1, t2;
-- echo End of 5.0 tests -- echo End of 5.0 tests
--echo #
--echo # BUG#727667 Wrong result with OR + NOT NULL in maria-5.3
--echo #
CREATE TABLE t1 (
f3 int(11),
f10 varchar(1),
KEY (f3)
);
INSERT INTO t1 VALUES ('9','k'),(NULL,'r');
SELECT * FROM t1 WHERE (f3 = 83) OR (f10 = 'z' AND f3 IS NULL);
DROP TABLE t1;

64
sql/sql_select.cc
View File

@@ -6611,10 +6611,12 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
j->ref.has_record= FALSE; j->ref.has_record= FALSE;
j->ref.null_rejecting= 0; j->ref.null_rejecting= 0;
j->ref.disable_cache= FALSE; j->ref.disable_cache= FALSE;
j->ref.null_ref_part= NO_REF_PART;
keyuse=org_keyuse; keyuse=org_keyuse;
store_key **ref_key= j->ref.key_copy; store_key **ref_key= j->ref.key_copy;
uchar *key_buff=j->ref.key_buff, *null_ref_key= 0; uchar *key_buff=j->ref.key_buff, *null_ref_key= 0;
uint null_ref_part= NO_REF_PART;
bool keyuse_uses_no_tables= TRUE; bool keyuse_uses_no_tables= TRUE;
if (ftkey) if (ftkey)
{ {
@@ -6668,7 +6670,10 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
instead of JT_REF_OR_NULL in case if field can't be null instead of JT_REF_OR_NULL in case if field can't be null
*/ */
if ((keyuse->optimize & KEY_OPTIMIZE_REF_OR_NULL) && maybe_null) if ((keyuse->optimize & KEY_OPTIMIZE_REF_OR_NULL) && maybe_null)
{
null_ref_key= key_buff; null_ref_key= key_buff;
null_ref_part= i;
}
key_buff+= keyinfo->key_part[i].store_length; key_buff+= keyinfo->key_part[i].store_length;
} }
} /* not ftkey */ } /* not ftkey */
@@ -6683,6 +6688,7 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
/* Must read with repeat */ /* Must read with repeat */
j->type= null_ref_key ? JT_REF_OR_NULL : JT_REF; j->type= null_ref_key ? JT_REF_OR_NULL : JT_REF;
j->ref.null_ref_key= null_ref_key; j->ref.null_ref_key= null_ref_key;
j->ref.null_ref_part= null_ref_part;
} }
else if (keyuse_uses_no_tables) else if (keyuse_uses_no_tables)
{ {
@@ -15356,8 +15362,12 @@ end_write_group(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
*****************************************************************************/ *****************************************************************************/
/** /**
Check if "left_item=right_item" equality is guaranteed to be true by use of
[eq]ref access on left_item->field->table.
@return @return
1 if right_item is used removable reference key on left_item TRUE if right_item is used removable reference key on left_item
FALSE otherwise
*/ */
bool test_if_ref(Item *root_cond, Item_field *left_item,Item *right_item) bool test_if_ref(Item *root_cond, Item_field *left_item,Item *right_item)
@@ -15370,7 +15380,11 @@ bool test_if_ref(Item *root_cond, Item_field *left_item,Item *right_item)
(!join_tab->first_inner || (!join_tab->first_inner ||
*join_tab->first_inner->on_expr_ref == root_cond)) *join_tab->first_inner->on_expr_ref == root_cond))
{ {
// Cond guards /*
If ref access uses "Full scan on NULL key" (i.e. it actually alternates
between ref access and full table scan), then no equality can be
guaranteed to be true.
*/
for (uint i = 0; i < join_tab->ref.key_parts; i++) for (uint i = 0; i < join_tab->ref.key_parts; i++)
{ {
if (join_tab->ref.cond_guards[i]) if (join_tab->ref.cond_guards[i])
@@ -15378,7 +15392,7 @@ bool test_if_ref(Item *root_cond, Item_field *left_item,Item *right_item)
return FALSE; return FALSE;
} }
} }
//
Item *ref_item=part_of_refkey(field->table,field); Item *ref_item=part_of_refkey(field->table,field);
if (ref_item && ref_item->eq(right_item,1)) if (ref_item && ref_item->eq(right_item,1))
{ {
@@ -15680,6 +15694,29 @@ make_cond_after_sjm(Item *root_cond, Item *cond, table_map tables,
} }
/*
@brief
Check if
- @table uses "ref"-like access
- it is based on "@field=certain_item" equality
- the equality will be true for any record returned by the access method
and return the certain_item if yes.
@detail
Equality won't necessarily hold if:
- the used index covers only part of the @field.
Suppose, we have a CHAR(5) field and INDEX(field(3)). if you make a lookup
for 'abc', you will get both record with 'abc' and with 'abcde'.
- The type of access is actually ref_or_null, and so @field can be either
a value or NULL.
@return
Item that the field will be equal to
NULL if no such item
*/
static Item * static Item *
part_of_refkey(TABLE *table,Field *field) part_of_refkey(TABLE *table,Field *field)
{ {
@@ -15688,18 +15725,31 @@ part_of_refkey(TABLE *table,Field *field)
return (Item*) 0; // field from outer non-select (UPDATE,...) return (Item*) 0; // field from outer non-select (UPDATE,...)
uint ref_parts= join_tab->ref.key_parts; uint ref_parts= join_tab->ref.key_parts;
if (ref_parts) if (ref_parts) /* if it's ref/eq_ref/ref_or_null */
{ {
uint key= join_tab->ref.key; uint key= join_tab->ref.key;
KEY *key_info= join_tab->get_keyinfo_by_key_no(key); KEY *key_info= join_tab->get_keyinfo_by_key_no(key);
KEY_PART_INFO *key_part= key_info->key_part; KEY_PART_INFO *key_part= key_info->key_part;
for (uint part=0 ; part < ref_parts ; part++,key_part++) for (uint part=0 ; part < ref_parts ; part++,key_part++)
if (field->eq(key_part->field) && {
!(key_part->key_part_flag & (HA_PART_KEY_SEG | HA_NULL_PART))) if (field->eq(key_part->field))
{
/*
Found the field in the key. Check that
1. ref_or_null doesn't alternate this component between a value and
a NULL
2. index fully covers the key
*/
if (part != join_tab->ref.null_ref_part && // (1)
!(key_part->key_part_flag & HA_PART_KEY_SEG)) // (2)
{
return join_tab->ref.items[part]; return join_tab->ref.items[part];
} }
break;
}
}
}
return (Item*) 0; return (Item*) 0;
} }

10
sql/sql_select.h
View File

@@ -79,6 +79,8 @@ typedef struct keyuse_t {
class store_key; class store_key;
const int NO_REF_PART= uint(-1);
typedef struct st_table_ref typedef struct st_table_ref
{ {
bool key_err; bool key_err;
@@ -109,8 +111,16 @@ typedef struct st_table_ref
*/ */
key_part_map null_rejecting; key_part_map null_rejecting;
table_map depend_map; ///< Table depends on these tables. table_map depend_map; ///< Table depends on these tables.
/* null byte position in the key_buf. Used for REF_OR_NULL optimization */ /* null byte position in the key_buf. Used for REF_OR_NULL optimization */
uchar *null_ref_key; uchar *null_ref_key;
/*
ref_or_null optimization: number of key part that alternates between
the lookup value or NULL (there's only one such part).
If we're not using ref_or_null, the value is NO_REF_PART
*/
uint null_ref_part;
/* /*
The number of times the record associated with this key was used The number of times the record associated with this key was used
in the join. in the join.

2
sql/table.cc
View File

@@ -1581,6 +1581,8 @@ static int open_binary_frm(THD *thd, TABLE_SHARE *share, uchar *head,
#endif #endif
key_part->key_part_flag|= HA_PART_KEY_SEG; key_part->key_part_flag|= HA_PART_KEY_SEG;
} }
if (field->real_maybe_null())
key_part->key_part_flag|= HA_NULL_PART;
/* /*
Sometimes we can compare key parts for equality with memcmp. Sometimes we can compare key parts for equality with memcmp.
But not always. But not always.