WindowResultSet (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl
- - org.apache.derby.impl.sql.execute.NoPutResultSetImpl
  - - org.apache.derby.impl.sql.execute.WindowResultSet

All Implemented Interfaces:

NoPutResultSet, ResultSet, RowLocationRetRowSource, RowSource
```
class WindowResultSet
extends NoPutResultSetImpl
```
WindowResultSet This ResultSet handles a window function ResultSet. The ResultSet is opened using openCore(). Each row is fetched and any restrictions evaluated for each row in a do-while loop in getNextRowCore(). The ResultSet is closed using closeCore().

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl
  BasicNoPutResultSetImpl.FieldComparator

Field Summary

Fields
Modifier and Type	Field	Description
`private ExecRow`	`allocatedRow`
`private FormatableBitSet`	`referencedColumns`
`private GeneratedMethod`	`restriction`
`long`	`restrictionTime`	Cumulative time needed to evaluate any restriction on this result set.
`private long`	`rownumber`
`NoPutResultSet`	`source`	Source result set,

Fields inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl
activation, beginTime, closeTime, compactRow, constructorTime, currentRow, endExecutionTime, finished, isOpen, isTopResultSet, nextTime, numOpens, openTime, optimizerEstimatedCost, optimizerEstimatedRowCount, resultDescription, rowsFiltered, rowsSeen, startExecutionTime, subqueryTrackingArray

Fields inherited from interface org.apache.derby.iapi.sql.execute.NoPutResultSet
ABSOLUTE, FIRST, LAST, NEXT, PREVIOUS, RELATIVE, TEMPORARY_RESULT_SET_NUMBER

Fields inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl
checkNullCols, clonedExecRow, cncLen, resultSetNumber, targetResultSet

Fields inherited from interface org.apache.derby.iapi.sql.ResultSet
CURRENT_RESULTSET_ONLY, ENTIRE_RESULTSET_TREE, ISAFTERLAST, ISBEFOREFIRST, ISFIRST, ISLAST

Constructor Summary

Constructors
Constructor	Description
`WindowResultSet(Activation activation, NoPutResultSet source, int rowAllocator, int resultSetNumber, int erdNumber, GeneratedMethod restriction, double optimizerEstimatedRowCount, double optimizerEstimatedCost)`	Constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`close()`	If the result set has been opened, close the open scan, else throw.
`private ExecRow`	`getAllocatedRow()`	Cache the ExecRow for this result set.
`ExecRow`	`getNextRowCore()`	Return the requested values computed from the next row (if any) for which the restriction evaluates to true.
`long`	`getTimeSpent(int type)`	Return the total amount of time spent in this ResultSet
`void`	`openCore()`	Open this ResultSet.
`void`	`populateFromSourceRow(ExecRow srcrow, ExecRow destrow)`	Copy columns from srcrow into destrow, or insert ROW_NUMBER.
`void`	`reopenCore()`	Reopen this ResultSet.

Methods inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl
addWarning, attachStatementContext, checkCancellationFlag, checkRowPosition, childrenToXML, cleanUp, dumpTimeStats, finish, finishAndRTS, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCompactRow, getCurrentTimeMillis, getElapsedMillis, getEndExecutionTimestamp, getEstimatedRowCount, getExecuteTime, getExecutionFactory, getFirstRow, getLanguageConnectionContext, getLastRow, getNextRow, getPointOfAttachment, getPreviousRow, getRelativeRow, getRowNumber, getScanIsolationLevel, getSubqueryTrackingArray, getTransactionController, getWarnings, isClosed, isXplainOnlyMode, markAsTopResultSet, modifiedRowCount, open, recordConstructorTime, requiresRelocking, returnsRows, setAfterLastRow, setBeforeFirstRow, setCompactRow, setCompatRow, toXML, toXML

Methods inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl
clearCurrentRow, clearOrderableCache, closeRowSource, getCursorName, getNextRowFromRowSource, getResultDescription, getValidColumns, isForUpdate, markRowAsDeleted, needsRowLocation, needsRowLocationForDeferredCheckConstraints, needsToClone, offendingRowLocation, positionScanAtRowLocation, printQualifiers, resultSetNumber, rowLocation, setCurrentRow, setHasDeferrableChecks, setNeedsRowLocation, setTargetResultSet, skipRow, skipScan, unpackHashValue, updateRow

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - restriction
```
private GeneratedMethod restriction
```
  - source
```
public NoPutResultSet source
```
    Source result set,
  - restrictionTime
```
public long restrictionTime
```
    Cumulative time needed to evaluate any restriction on this result set.
  - referencedColumns
```
private FormatableBitSet referencedColumns
```
  - allocatedRow
```
private ExecRow allocatedRow
```
  - rownumber
```
private long rownumber
```
- Constructor Detail
  - WindowResultSet
```
WindowResultSet(Activation activation,
                NoPutResultSet source,
                int rowAllocator,
                int resultSetNumber,
                int erdNumber,
                GeneratedMethod restriction,
                double optimizerEstimatedRowCount,
                double optimizerEstimatedCost)
         throws StandardException
```
    Constructor
    
    Parameters:
    
    activation - The activation
    
    source - Source result set
    
    rowAllocator -
    
    resultSetNumber - The resultSetNumber
    
    erdNumber - Int for ResultDescription (so it can be turned back into an object)
    
    restriction - Restriction
    
    optimizerEstimatedRowCount - The optimizer's estimated number of rows.
    
    optimizerEstimatedCost - The optimizer's estimated cost
    
    Throws:
    
    StandardException
- Method Detail
  - openCore
```
public void openCore()
              throws StandardException
```
    Open this ResultSet.
    
    Throws:
    
    StandardException - thrown if cursor finished.
  - reopenCore
```
public void reopenCore()
                throws StandardException
```
    Reopen this ResultSet.
    
    Specified by:
    
    reopenCore in interface NoPutResultSet
    
    Overrides:
    
    reopenCore in class BasicNoPutResultSetImpl
    
    Throws:
    
    StandardException - thrown if cursor finished.
    
    See Also:
    
    NoPutResultSet.openCore()
  - getNextRowCore
```
public ExecRow getNextRowCore()
                       throws StandardException
```
    Return the requested values computed from the next row (if any) for which the restriction evaluates to true.
    Restriction and projection parameters are evaluated for each row.
    
    Specified by:
    
    getNextRowCore in interface NoPutResultSet
    
    Specified by:
    
    getNextRowCore in class BasicNoPutResultSetImpl
    
    Returns:
    
    the next row in the result
    
    Throws:
    
    StandardException - thrown on failure.
    
    StandardException - ResultSetNotOpen thrown if not yet open.
    
    See Also:
    
    NoPutResultSet.getNextRowCore()
  - close
```
public void close()
           throws StandardException
```
    If the result set has been opened, close the open scan, else throw.
    
    Specified by:
    
    close in interface ResultSet
    
    Overrides:
    
    close in class NoPutResultSetImpl
    
    Throws:
    
    StandardException - thrown on error
  - populateFromSourceRow
```
public void populateFromSourceRow(ExecRow srcrow,
                                  ExecRow destrow)
                           throws StandardException
```
    Copy columns from srcrow into destrow, or insert ROW_NUMBER.
    FIXME This is temporary. Window function treatment needs to generalized to work for other window functions.
    
    Throws:
    
    StandardException - thrown on failure to open
  - getTimeSpent
```
public long getTimeSpent(int type)
```
    Return the total amount of time spent in this ResultSet
    
    Parameters:
    
    type - CURRENT_RESULTSET_ONLY - time spent only in this ResultSet ENTIRE_RESULTSET_TREE - time spent in this ResultSet and below.
    
    Returns:
    
    long The total amount of time spent (in milliseconds).
  - getAllocatedRow
```
private ExecRow getAllocatedRow()
                         throws StandardException
```
    Cache the ExecRow for this result set.
    
    Returns:
    
    The cached ExecRow for this ResultSet
    
    Throws:
    
    StandardException - thrown on failure.

Class WindowResultSet

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

Field Summary

Fields inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

Fields inherited from interface org.apache.derby.iapi.sql.execute.NoPutResultSet

Fields inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl

Fields inherited from interface org.apache.derby.iapi.sql.ResultSet

Constructor Summary

Method Summary

Methods inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

Methods inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl

Methods inherited from class java.lang.Object

Field Detail

restriction

source

restrictionTime

referencedColumns

allocatedRow

rownumber

Constructor Detail

WindowResultSet

Method Detail

openCore

reopenCore

getNextRowCore

close

populateFromSourceRow

getTimeSpent

getAllocatedRow