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Administrator
h2database
Commits
d5f157b6
Unverified
提交
d5f157b6
authored
7月 24, 2018
作者:
Evgenij Ryazanov
提交者:
GitHub
7月 24, 2018
浏览文件
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浏览文件
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差异文件
Merge pull request #1321 from katzyn/offset
Do not add rows before OFFSET to result if possible
上级
27a74b26
8968c0b6
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
89 行增加
和
32 行删除
+89
-32
Select.java
h2/src/main/org/h2/command/dml/Select.java
+74
-32
select.sql
h2/src/test/org/h2/test/scripts/dml/select.sql
+15
-0
没有找到文件。
h2/src/main/org/h2/command/dml/Select.java
浏览文件 @
d5f157b6
...
...
@@ -302,8 +302,9 @@ public class Select extends Query {
return
condition
;
}
private
LazyResult
queryGroupSorted
(
int
columnCount
,
ResultTarget
result
)
{
private
LazyResult
queryGroupSorted
(
int
columnCount
,
ResultTarget
result
,
long
offset
,
boolean
quickOffset
)
{
LazyResultGroupSorted
lazyResult
=
new
LazyResultGroupSorted
(
expressionArray
,
columnCount
);
skipOffset
(
lazyResult
,
offset
,
quickOffset
);
if
(
result
==
null
)
{
return
lazyResult
;
}
...
...
@@ -428,7 +429,7 @@ public class Select extends Query {
return
condition
==
null
||
condition
.
getBooleanValue
(
session
);
}
private
void
queryGroup
(
int
columnCount
,
LocalResult
result
)
{
private
void
queryGroup
(
int
columnCount
,
LocalResult
result
,
long
offset
,
boolean
quickOffset
)
{
groupByData
=
new
HashMap
<>();
currentGroupByExprData
=
null
;
currentGroupsKey
=
null
;
...
...
@@ -494,6 +495,10 @@ public class Select extends Query {
if
(
isHavingNullOrFalse
(
row
))
{
continue
;
}
if
(
quickOffset
&&
offset
>
0
)
{
offset
--;
continue
;
}
row
=
keepOnlyDistinct
(
row
,
columnCount
);
result
.
addRow
(
row
);
}
...
...
@@ -586,14 +591,13 @@ public class Select extends Query {
return
null
;
}
private
void
queryDistinct
(
ResultTarget
result
,
long
limitRows
,
boolean
withTies
)
{
// limitRows must be long, otherwise we get an int overflow
// if limitRows is at or near Integer.MAX_VALUE
// limitRows is never 0 here
if
(
limitRows
>
0
&&
offsetExpr
!=
null
)
{
int
offset
=
offsetExpr
.
getValue
(
session
).
getInt
();
if
(
offset
>
0
)
{
private
void
queryDistinct
(
ResultTarget
result
,
long
offset
,
long
limitRows
,
boolean
withTies
,
boolean
quickOffset
)
{
if
(
limitRows
>
0
&&
offset
>
0
)
{
limitRows
+=
offset
;
if
(
limitRows
<
0
)
{
// Overflow
limitRows
=
Long
.
MAX_VALUE
;
}
}
int
rowNumber
=
0
;
...
...
@@ -602,8 +606,11 @@ public class Select extends Query {
SearchRow
first
=
null
;
int
columnIndex
=
index
.
getColumns
()[
0
].
getColumnId
();
int
sampleSize
=
getSampleSizeValue
(
session
);
if
(!
quickOffset
)
{
offset
=
0
;
}
while
(
true
)
{
setCurrentRowNumber
(
rowNumber
+
1
);
setCurrentRowNumber
(
++
rowNumber
);
Cursor
cursor
=
index
.
findNext
(
session
,
first
,
null
);
if
(!
cursor
.
next
())
{
break
;
...
...
@@ -614,9 +621,12 @@ public class Select extends Query {
first
=
topTableFilter
.
getTable
().
getTemplateSimpleRow
(
true
);
}
first
.
setValue
(
columnIndex
,
value
);
if
(
offset
>
0
)
{
offset
--;
continue
;
}
Value
[]
row
=
{
value
};
result
.
addRow
(
row
);
rowNumber
++;
if
((
sort
==
null
||
sortUsingIndex
)
&&
limitRows
>
0
&&
rowNumber
>=
limitRows
&&
!
withTies
)
{
break
;
...
...
@@ -627,24 +637,24 @@ public class Select extends Query {
}
}
private
LazyResult
queryFlat
(
int
columnCount
,
ResultTarget
result
,
long
limitRows
,
boolean
withTies
)
{
// limitRows must be long, otherwise we get an int overflow
// if limitRows is at or near Integer.MAX_VALUE
// limitRows is never 0 here
if
(
limitRows
>
0
&&
offsetExpr
!=
null
)
{
int
offset
=
offsetExpr
.
getValue
(
session
).
getInt
();
if
(
offset
>
0
)
{
private
LazyResult
queryFlat
(
int
columnCount
,
ResultTarget
result
,
long
offset
,
long
limitRows
,
boolean
withTies
,
boolean
quickOffset
)
{
if
(
limitRows
>
0
&&
offset
>
0
&&
!
quickOffset
)
{
limitRows
+=
offset
;
if
(
limitRows
<
0
)
{
// Overflow
limitRows
=
Long
.
MAX_VALUE
;
}
}
ArrayList
<
Row
>
forUpdateRows
=
this
.
isForUpdateMvcc
?
Utils
.<
Row
>
newSmallArrayList
()
:
null
;
int
sampleSize
=
getSampleSizeValue
(
session
);
LazyResultQueryFlat
lazyResult
=
new
LazyResultQueryFlat
(
expressionArray
,
sampleSize
,
columnCount
);
skipOffset
(
lazyResult
,
offset
,
quickOffset
);
if
(
result
==
null
)
{
return
lazyResult
;
}
if
(
sort
!=
null
&&
!
sortUsingIndex
||
limitRows
<
=
0
||
withTies
)
{
if
(
sort
!=
null
&&
!
sortUsingIndex
||
limitRows
<
0
||
withTies
)
{
limitRows
=
Long
.
MAX_VALUE
;
}
while
(
result
.
getRowCount
()
<
limitRows
&&
lazyResult
.
next
())
{
...
...
@@ -659,14 +669,24 @@ public class Select extends Query {
return
null
;
}
private
void
queryQuick
(
int
columnCount
,
ResultTarget
result
)
{
private
static
void
skipOffset
(
LazyResultSelect
lazyResult
,
long
offset
,
boolean
quickOffset
)
{
if
(
quickOffset
)
{
while
(
offset
>
0
&&
lazyResult
.
next
())
{
offset
--;
}
}
}
private
void
queryQuick
(
int
columnCount
,
ResultTarget
result
,
boolean
skipResult
)
{
Value
[]
row
=
new
Value
[
columnCount
];
for
(
int
i
=
0
;
i
<
columnCount
;
i
++)
{
Expression
expr
=
expressions
.
get
(
i
);
row
[
i
]
=
expr
.
getValue
(
session
);
}
if
(!
skipResult
)
{
result
.
addRow
(
row
);
}
}
@Override
public
ResultInterface
queryMeta
()
{
...
...
@@ -688,32 +708,48 @@ public class Select extends Query {
limitRows
=
Math
.
min
(
l
,
limitRows
);
}
}
long
offset
;
if
(
offsetExpr
!=
null
)
{
offset
=
offsetExpr
.
getValue
(
session
).
getLong
();
if
(
offset
<
0
)
{
offset
=
0
;
}
}
else
{
offset
=
0
;
}
boolean
lazy
=
session
.
isLazyQueryExecution
()
&&
target
==
null
&&
!
isForUpdate
&&
!
isQuickAggregateQuery
&&
limitRows
!=
0
&&
!
withTies
&&
offset
Expr
==
null
&&
isReadOnly
();
limitRows
!=
0
&&
!
withTies
&&
offset
==
0
&&
isReadOnly
();
int
columnCount
=
expressions
.
size
();
LocalResult
result
=
null
;
if
(!
lazy
&&
(
target
==
null
||
!
session
.
getDatabase
().
getSettings
().
optimizeInsertFromSelect
))
{
result
=
createLocalResult
(
result
);
}
// Do not add rows before OFFSET to result if possible
boolean
quickOffset
=
true
;
if
(
sort
!=
null
&&
(!
sortUsingIndex
||
isAnyDistinct
()
||
withTies
))
{
result
=
createLocalResult
(
result
);
result
.
setSortOrder
(
sort
);
if
(!
sortUsingIndex
)
{
quickOffset
=
false
;
}
}
if
(
distinct
)
{
if
(!
isDistinctQuery
)
{
quickOffset
=
false
;
result
=
createLocalResult
(
result
);
result
.
setDistinct
();
}
}
else
if
(
distinctExpressions
!=
null
)
{
quickOffset
=
false
;
result
=
createLocalResult
(
result
);
result
.
setDistinct
(
distinctIndexes
);
}
if
(
isGroupQuery
&&
!
isGroupSortedQuery
)
{
result
=
createLocalResult
(
result
);
}
if
(!
lazy
&&
(
limitRows
>=
0
||
offset
Expr
!=
null
))
{
if
(!
lazy
&&
(
limitRows
>=
0
||
offset
>
0
))
{
result
=
createLocalResult
(
result
);
}
topTableFilter
.
startQuery
(
session
);
...
...
@@ -741,17 +777,20 @@ public class Select extends Query {
if
(
limitRows
!=
0
)
{
try
{
if
(
isQuickAggregateQuery
)
{
queryQuick
(
columnCount
,
to
);
queryQuick
(
columnCount
,
to
,
quickOffset
&&
offset
>
0
);
}
else
if
(
isGroupQuery
)
{
if
(
isGroupSortedQuery
)
{
lazyResult
=
queryGroupSorted
(
columnCount
,
to
);
lazyResult
=
queryGroupSorted
(
columnCount
,
to
,
offset
,
quickOffset
);
}
else
{
queryGroup
(
columnCount
,
result
);
queryGroup
(
columnCount
,
result
,
offset
,
quickOffset
);
}
}
else
if
(
isDistinctQuery
)
{
queryDistinct
(
to
,
limitRows
,
withTies
);
queryDistinct
(
to
,
offset
,
limitRows
,
withTies
,
quickOffset
);
}
else
{
lazyResult
=
queryFlat
(
columnCount
,
to
,
limitRows
,
withTies
);
lazyResult
=
queryFlat
(
columnCount
,
to
,
offset
,
limitRows
,
withTies
,
quickOffset
);
}
if
(
quickOffset
)
{
offset
=
0
;
}
}
finally
{
if
(!
lazy
)
{
...
...
@@ -770,8 +809,11 @@ public class Select extends Query {
return
lazyResult
;
}
}
if
(
offsetExpr
!=
null
)
{
result
.
setOffset
(
offsetExpr
.
getValue
(
session
).
getInt
());
if
(
offset
!=
0
)
{
if
(
offset
>
Integer
.
MAX_VALUE
)
{
throw
DbException
.
getInvalidValueException
(
"OFFSET"
,
offset
);
}
result
.
setOffset
((
int
)
offset
);
}
if
(
limitRows
>=
0
)
{
result
.
setLimit
(
limitRows
);
...
...
h2/src/test/org/h2/test/scripts/dml/select.sql
浏览文件 @
d5f157b6
...
...
@@ -148,3 +148,18 @@ SELECT A, B FROM TEST ORDER BY A FETCH FIRST 1 ROW WITH TIES;
DROP
TABLE
TEST
;
>
ok
CREATE
TABLE
TEST
(
A
INT
,
B
INT
);
>
ok
INSERT
INTO
TEST
VALUES
(
1
,
1
),
(
1
,
2
),
(
2
,
1
),
(
2
,
2
),
(
2
,
3
);
>
update
count
:
5
SELECT
A
,
COUNT
(
B
)
FROM
TEST
GROUP
BY
A
OFFSET
1
;
>
A
COUNT
(
B
)
>
-
--------
>
2
3
>
rows
:
1
DROP
TABLE
TEST
;
>
ok
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