org.apache.derby.impl.store.access.sort
Class SortBufferScan

java.lang.Object
  extended byorg.apache.derby.impl.store.access.sort.Scan
      extended byorg.apache.derby.impl.store.access.sort.SortScan
          extended byorg.apache.derby.impl.store.access.sort.SortBufferScan
All Implemented Interfaces:
GenericScanController, GroupFetchScanController, RowCountable, ScanController, ScanInfo, ScanManager

public class SortBufferScan
extends SortScan

A sort scan that just reads rows out of a sorter.


Field Summary
protected  SortBuffer sortBuffer
          The sorter we're returning rows from.
 
Fields inherited from class org.apache.derby.impl.store.access.sort.SortScan
current, hold, sort, tran
 
Fields inherited from interface org.apache.derby.iapi.store.access.ScanController
GE, GT, NA
 
Constructor Summary
(package private) SortBufferScan(MergeSort sort, TransactionManager tran, SortBuffer sortBuffer, boolean hold)
           
 
Method Summary
 void close()
          Close the scan.
 boolean closeForEndTransaction(boolean closeHeldScan)
          Close the scan.
 boolean next()
          Move to the next position in the scan.
 
Methods inherited from class org.apache.derby.impl.store.access.sort.SortScan
fetch, fetchNext
 
Methods inherited from class org.apache.derby.impl.store.access.sort.Scan
delete, didNotQualify, doesCurrentPositionQualify, fetchLocation, fetchNextGroup, fetchNextGroup, fetchSet, getAllScanInfo, getEstimatedRowCount, getScanInfo, isCurrentPositionDeleted, isKeyed, isTableLocked, newRowLocationTemplate, reopenScan, reopenScanByRowLocation, replace, savePosition, setEstimatedRowCount
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

sortBuffer

protected SortBuffer sortBuffer
The sorter we're returning rows from.

Constructor Detail

SortBufferScan

SortBufferScan(MergeSort sort,
               TransactionManager tran,
               SortBuffer sortBuffer,
               boolean hold)
Method Detail

next

public boolean next()
             throws StandardException
Move to the next position in the scan.

Returns:
True if there is a next position in the scan, false if there isn't.
Throws:
StandardException - Standard exception policy.
See Also:
ScanController.next()

closeForEndTransaction

public boolean closeForEndTransaction(boolean closeHeldScan)
Close the scan.

Parameters:
closeHeldScan - If true, means to close scan even if it has been opened to be kept opened across commit. This is used to close these scans on abort.
Returns:
boolean indicating that the close has resulted in a real close of the scan. A held scan will return false if called by closeForEndTransaction(false), otherwise it will return true. A non-held scan will always return true.

close

public void close()
Close the scan.

Specified by:
close in interface GenericScanController
Overrides:
close in class SortScan
See Also:
GenericScanController.close()

Built on Mon 2007-06-04 09:58:47+0400, from revision ???

Apache Derby V10.1 Engine Documentation - Copyright © 1997,2005 The Apache Software Foundation or its licensors, as applicable.