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h2database
Commits
d9e6e1e4
提交
d9e6e1e4
authored
6 年前
作者:
Evgenij Ryazanov
浏览文件
操作
浏览文件
下载
电子邮件补丁
差异文件
Improve cost calculation for multi-column indexes
上级
37047454
显示空白字符变更
内嵌
并排
正在显示
2 个修改的文件
包含
53 行增加
和
6 行删除
+53
-6
BaseIndex.java
h2/src/main/org/h2/index/BaseIndex.java
+13
-6
indexes.sql
h2/src/test/org/h2/test/scripts/indexes.sql
+40
-0
没有找到文件。
h2/src/main/org/h2/index/BaseIndex.java
浏览文件 @
d9e6e1e4
...
@@ -168,12 +168,13 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
...
@@ -168,12 +168,13 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
int
totalSelectivity
=
0
;
int
totalSelectivity
=
0
;
long
rowsCost
=
rowCount
;
long
rowsCost
=
rowCount
;
if
(
masks
!=
null
)
{
if
(
masks
!=
null
)
{
for
(
int
i
=
0
,
len
=
columns
.
length
;
i
<
len
;
i
++)
{
int
i
=
0
,
len
=
columns
.
length
;
Column
column
=
columns
[
i
];
while
(
i
<
len
)
{
Column
column
=
columns
[
i
++];
int
index
=
column
.
getColumnId
();
int
index
=
column
.
getColumnId
();
int
mask
=
masks
[
index
];
int
mask
=
masks
[
index
];
if
((
mask
&
IndexCondition
.
EQUALITY
)
==
IndexCondition
.
EQUALITY
)
{
if
((
mask
&
IndexCondition
.
EQUALITY
)
==
IndexCondition
.
EQUALITY
)
{
if
(
i
==
columns
.
length
-
1
&&
getIndexType
().
isUnique
())
{
if
(
i
==
len
&&
getIndexType
().
isUnique
())
{
rowsCost
=
3
;
rowsCost
=
3
;
break
;
break
;
}
}
...
@@ -185,18 +186,24 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
...
@@ -185,18 +186,24 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
}
}
rowsCost
=
2
+
Math
.
max
(
rowCount
/
distinctRows
,
1
);
rowsCost
=
2
+
Math
.
max
(
rowCount
/
distinctRows
,
1
);
}
else
if
((
mask
&
IndexCondition
.
RANGE
)
==
IndexCondition
.
RANGE
)
{
}
else
if
((
mask
&
IndexCondition
.
RANGE
)
==
IndexCondition
.
RANGE
)
{
rowsCost
=
2
+
row
Coun
t
/
4
;
rowsCost
=
2
+
row
sCos
t
/
4
;
break
;
break
;
}
else
if
((
mask
&
IndexCondition
.
START
)
==
IndexCondition
.
START
)
{
}
else
if
((
mask
&
IndexCondition
.
START
)
==
IndexCondition
.
START
)
{
rowsCost
=
2
+
row
Coun
t
/
3
;
rowsCost
=
2
+
row
sCos
t
/
3
;
break
;
break
;
}
else
if
((
mask
&
IndexCondition
.
END
)
==
IndexCondition
.
END
)
{
}
else
if
((
mask
&
IndexCondition
.
END
)
==
IndexCondition
.
END
)
{
rowsCost
=
row
Coun
t
/
3
;
rowsCost
=
row
sCos
t
/
3
;
break
;
break
;
}
else
{
}
else
{
if
(
mask
==
0
)
{
// Adjust counter of used columns (i)
i
--;
}
break
;
break
;
}
}
}
}
// Increase cost of indexes with additional unused columns
rowsCost
+=
len
-
i
;
}
}
// If the ORDER BY clause matches the ordering of this index,
// If the ORDER BY clause matches the ordering of this index,
// it will be cheaper than another index, so adjust the cost
// it will be cheaper than another index, so adjust the cost
...
...
This diff is collapsed.
Click to expand it.
h2/src/test/org/h2/test/scripts/indexes.sql
浏览文件 @
d9e6e1e4
...
@@ -304,3 +304,43 @@ select 1 from test group by x;
...
@@ -304,3 +304,43 @@ select 1 from test group by x;
drop
table
test
;
drop
table
test
;
>
ok
>
ok
CREATE
TABLE
TEST
(
A
INT
,
B
INT
,
C
INT
);
>
ok
CREATE
INDEX
T_A1
ON
TEST
(
A
);
>
ok
CREATE
INDEX
T_A_B
ON
TEST
(
A
,
B
);
>
ok
CREATE
INDEX
T_A_C
ON
TEST
(
A
,
C
);
>
ok
EXPLAIN
SELECT
*
FROM
TEST
WHERE
A
=
0
;
>>
SELECT
TEST
.
A
,
TEST
.
B
,
TEST
.
C
FROM
PUBLIC
.
TEST
/* PUBLIC.T_A1: A = 0 */
WHERE
A
=
0
EXPLAIN
SELECT
*
FROM
TEST
WHERE
A
=
0
AND
B
>=
0
;
>>
SELECT
TEST
.
A
,
TEST
.
B
,
TEST
.
C
FROM
PUBLIC
.
TEST
/* PUBLIC.T_A_B: A = 0 AND B >= 0 */
WHERE
(
A
=
0
)
AND
(
B
>=
0
)
INSERT
INTO
TEST
(
SELECT
X
/
100
,
X
,
X
FROM
SYSTEM_RANGE
(
1
,
3000
));
>
update
count
:
3000
EXPLAIN
SELECT
*
FROM
TEST
WHERE
A
=
0
;
>>
SELECT
TEST
.
A
,
TEST
.
B
,
TEST
.
C
FROM
PUBLIC
.
TEST
/* PUBLIC.T_A1: A = 0 */
WHERE
A
=
0
EXPLAIN
SELECT
*
FROM
TEST
WHERE
A
=
0
AND
B
>=
0
;
>>
SELECT
TEST
.
A
,
TEST
.
B
,
TEST
.
C
FROM
PUBLIC
.
TEST
/* PUBLIC.T_A_B: A = 0 AND B >= 0 */
WHERE
(
A
=
0
)
AND
(
B
>=
0
)
-- Test that creation order of indexes has no effect
CREATE
INDEX
T_A2
ON
TEST
(
A
);
>
ok
DROP
INDEX
T_A1
;
>
ok
EXPLAIN
SELECT
*
FROM
TEST
WHERE
A
=
0
;
>>
SELECT
TEST
.
A
,
TEST
.
B
,
TEST
.
C
FROM
PUBLIC
.
TEST
/* PUBLIC.T_A2: A = 0 */
WHERE
A
=
0
DROP
TABLE
TEST
;
>
ok
This diff is collapsed.
Click to expand it.
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