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h2database
Commits
dc268c8b
提交
dc268c8b
authored
9 年前
作者:
Noel Grandin
浏览文件
操作
浏览文件
下载
电子邮件补丁
差异文件
format and remove some debug
上级
1e48ee39
隐藏空白字符变更
内嵌
并排
正在显示
1 个修改的文件
包含
64 行增加
和
63 行删除
+64
-63
BaseIndex.java
h2/src/main/org/h2/index/BaseIndex.java
+64
-63
没有找到文件。
h2/src/main/org/h2/index/BaseIndex.java
浏览文件 @
dc268c8b
...
...
@@ -160,47 +160,47 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
* @param sortOrder the sort order
* @return the estimated cost
*/
protected
final
long
getCostRangeIndex
(
int
[]
masks
,
long
rowCount
,
TableFilter
[]
filters
,
int
filter
,
SortOrder
sortOrder
,
boolean
isScanIndex
)
{
rowCount
+=
Constants
.
COST_ROW_OFFSET
;
protected
final
long
getCostRangeIndex
(
int
[]
masks
,
long
rowCount
,
TableFilter
[]
filters
,
int
filter
,
SortOrder
sortOrder
,
boolean
isScanIndex
)
{
rowCount
+=
Constants
.
COST_ROW_OFFSET
;
int
totalSelectivity
=
0
;
long
rowsCost
=
rowCount
;
if
(
masks
!=
null
)
{
for
(
int
i
=
0
,
len
=
columns
.
length
;
i
<
len
;
i
++)
{
Column
column
=
columns
[
i
];
int
index
=
column
.
getColumnId
();
int
mask
=
masks
[
index
];
if
((
mask
&
IndexCondition
.
EQUALITY
)
==
IndexCondition
.
EQUALITY
)
{
if
(
i
==
columns
.
length
-
1
&&
getIndexType
().
isUnique
())
{
rowsCost
=
3
;
break
;
}
totalSelectivity
=
100
-
((
100
-
totalSelectivity
)
*
(
100
-
column
.
getSelectivity
())
/
100
);
long
distinctRows
=
rowCount
*
totalSelectivity
/
100
;
if
(
distinctRows
<=
0
)
{
distinctRows
=
1
;
}
rowsCost
=
2
+
Math
.
max
(
rowCount
/
distinctRows
,
1
);
}
else
if
((
mask
&
IndexCondition
.
RANGE
)
==
IndexCondition
.
RANGE
)
{
rowsCost
=
2
+
rowCount
/
4
;
break
;
}
else
if
((
mask
&
IndexCondition
.
START
)
==
IndexCondition
.
START
)
{
rowsCost
=
2
+
rowCount
/
3
;
break
;
}
else
if
((
mask
&
IndexCondition
.
END
)
==
IndexCondition
.
END
)
{
rowsCost
=
rowCount
/
3
;
break
;
}
else
{
break
;
}
}
for
(
int
i
=
0
,
len
=
columns
.
length
;
i
<
len
;
i
++)
{
Column
column
=
columns
[
i
];
int
index
=
column
.
getColumnId
();
int
mask
=
masks
[
index
];
if
((
mask
&
IndexCondition
.
EQUALITY
)
==
IndexCondition
.
EQUALITY
)
{
if
(
i
==
columns
.
length
-
1
&&
getIndexType
().
isUnique
())
{
rowsCost
=
3
;
break
;
}
totalSelectivity
=
100
-
((
100
-
totalSelectivity
)
*
(
100
-
column
.
getSelectivity
())
/
100
);
long
distinctRows
=
rowCount
*
totalSelectivity
/
100
;
if
(
distinctRows
<=
0
)
{
distinctRows
=
1
;
}
rowsCost
=
2
+
Math
.
max
(
rowCount
/
distinctRows
,
1
);
}
else
if
((
mask
&
IndexCondition
.
RANGE
)
==
IndexCondition
.
RANGE
)
{
rowsCost
=
2
+
rowCount
/
4
;
break
;
}
else
if
((
mask
&
IndexCondition
.
START
)
==
IndexCondition
.
START
)
{
rowsCost
=
2
+
rowCount
/
3
;
break
;
}
else
if
((
mask
&
IndexCondition
.
END
)
==
IndexCondition
.
END
)
{
rowsCost
=
rowCount
/
3
;
break
;
}
else
{
break
;
}
}
}
// If the ORDER BY clause matches the ordering of this index,
// it will be cheaper than another index, so adjust the cost accordingly.
// it will be cheaper than another index, so adjust the cost
// accordingly.
long
sortingCost
=
0
;
if
(
sortOrder
!=
null
)
{
sortingCost
=
100
+
rowCount
/
10
;
sortingCost
=
100
+
rowCount
/
10
;
}
if
(
sortOrder
!=
null
&&
!
isScanIndex
)
{
boolean
sortOrderMatches
=
true
;
...
...
@@ -239,43 +239,44 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
sortingCost
=
100
-
coveringCount
;
}
}
// If we have two indexes with the same cost, and one of the indexes can satisfy the query
// without needing to read from the primary table, make that one slightly lower cost.
// If we have two indexes with the same cost, and one of the indexes can
// satisfy the query without needing to read from the primary table,
// make that one slightly lower cost.
boolean
needsToReadFromScanIndex
=
true
;
if
(!
isScanIndex
)
{
HashSet
<
Column
>
set1
=
New
.
hashSet
();
for
(
int
i
=
0
;
i
<
filters
.
length
;
i
++)
{
if
(
filters
[
i
].
getSelect
()
!=
null
)
{
filters
[
i
].
getSelect
().
isEverything
(
ExpressionVisitor
.
getColumnsVisitor
(
set1
));
}
}
if
(!
set1
.
isEmpty
())
{
HashSet
<
Column
>
set2
=
New
.
hashSet
();
for
(
Column
c
:
set1
)
{
if
(
c
.
getTable
()
==
getTable
())
{
set2
.
add
(
c
);
}
}
set2
.
removeAll
(
Arrays
.
asList
(
columns
));
if
(
set2
.
isEmpty
())
{
needsToReadFromScanIndex
=
false
;
}
}
HashSet
<
Column
>
set1
=
New
.
hashSet
();
for
(
int
i
=
0
;
i
<
filters
.
length
;
i
++)
{
if
(
filters
[
i
].
getSelect
()
!=
null
)
{
filters
[
i
].
getSelect
().
isEverything
(
ExpressionVisitor
.
getColumnsVisitor
(
set1
));
}
}
if
(!
set1
.
isEmpty
())
{
HashSet
<
Column
>
set2
=
New
.
hashSet
();
for
(
Column
c
:
set1
)
{
if
(
c
.
getTable
()
==
getTable
())
{
set2
.
add
(
c
);
}
}
set2
.
removeAll
(
Arrays
.
asList
(
columns
));
if
(
set2
.
isEmpty
())
{
needsToReadFromScanIndex
=
false
;
}
}
}
long
rc
;
if
(
isScanIndex
)
{
rc
=
rowsCost
+
sortingCost
+
20
;
rc
=
rowsCost
+
sortingCost
+
20
;
}
else
if
(
needsToReadFromScanIndex
)
{
rc
=
rowsCost
+
rowsCost
+
sortingCost
+
20
;
rc
=
rowsCost
+
rowsCost
+
sortingCost
+
20
;
}
else
{
/* The (20-x) calculation makes sure that when we pick a covering index, we pick the covering
* index that has the smallest number of columns. This is faster because a smaller index will fit into
* fewer data blocks.
*/
rc
=
rowsCost
+
sortingCost
+
(
20
-
columns
.
length
);
/*
* The (20-x) calculation makes sure that when we pick a covering
* index, we pick the covering index that has the smallest number of
* columns. This is faster because a smaller index will fit into
* fewer data blocks.
*/
rc
=
rowsCost
+
sortingCost
+
(
20
-
columns
.
length
);
}
getDatabase
().
getTrace
(
0
).
debug
(
"needsToReadFromScanIndex "
+
needsToReadFromScanIndex
+
" isScanIndex "
+
isScanIndex
+
" rowsCost "
+
rowsCost
+
" rowCount "
+
rowCount
+
" sortingCost "
+
sortingCost
+
" rc "
+
rc
);
return
rc
;
}
...
...
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