org.apache.derby.impl.store.access.btree.index
Class B2IMaxScan
java.lang.Object
org.apache.derby.impl.store.access.btree.OpenBTree
org.apache.derby.impl.store.access.btree.BTreeScan
org.apache.derby.impl.store.access.btree.BTreeMaxScan
org.apache.derby.impl.store.access.btree.index.B2IMaxScan
- All Implemented Interfaces:
- ScanManager, GenericScanController, GroupFetchScanController, RowCountable, ScanController
public class B2IMaxScan
- extends BTreeMaxScan
Scan used to find maximum value in the secondary index.
This class implements an optimized interface to find the maximum row,
for a set of rows between an input start and stop key.
Note most work of this class is inherited from the generic btree implementation.
This class initializes the top level object and deals with locking information
specific to a secondary index implementation of a btree.
Fields inherited from class org.apache.derby.impl.store.access.btree.BTreeScan |
fetchNext_one_slot_array, init_fetchDesc, init_forUpdate, init_hold, init_lock_fetch_desc, init_qualifier, init_rawtran, init_scanColumnList, init_startKeyValue, init_startSearchOperator, init_stopKeyValue, init_stopSearchOperator, init_template, init_useUpdateLocks, lock_operation, SCAN_DONE, SCAN_HOLD_INIT, SCAN_HOLD_INPROGRESS, SCAN_INIT, SCAN_INPROGRESS, scan_state, stat_numdeleted_rows_visited, stat_numpages_visited, stat_numrows_qualified, stat_numrows_visited |
Method Summary |
void |
close()
Close the scan. |
boolean |
closeForEndTransaction(boolean closeHeldScan)
Close the scan, a commit or abort is about to happen. |
void |
init(TransactionManager xact_manager,
Transaction rawtran,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level,
boolean open_for_locking,
FormatableBitSet scanColumnList,
B2I conglomerate,
B2IUndo undo)
Initialize the scan for use. |
Methods inherited from class org.apache.derby.impl.store.access.btree.BTreeScan |
delete, didNotQualify, doesCurrentPositionQualify, fetch, fetchLocation, fetchNext, fetchNextGroup, fetchNextGroup, fetchSet, fetchWithoutQualify, getCurrentRecordHandleForDebugging, getScanInfo, init, isCurrentPositionDeleted, isHeldAfterCommit, isKeyed, newRowLocationTemplate, next, positionAtDoneScan, positionAtDoneScanFromClose, positionAtNextPage, positionAtRowLocation, positionAtStartForForwardScan, process_qualifier, reopenScan, reopenScanByRowLocation, replace, reposition, toString |
Methods inherited from class org.apache.derby.impl.store.access.btree.OpenBTree |
checkConsistency, debugConglomerate, getColumnSortOrderInfo, getConglomerate, getContainer, getContainerHandle, getEstimatedRowCount, getHeight, getHold, getLockingPolicy, getLockLevel, getOpenMode, getRawTran, getRuntimeMem, getSpaceInfo, getXactMgr, init, isClosed, isTableLocked, reopen, setEstimatedRowCount, setLockingPolicy, test_errors |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
base_cc_for_locking
private ConglomerateController base_cc_for_locking
B2IMaxScan
B2IMaxScan()
close
public void close()
throws StandardException
- Close the scan.
- Specified by:
close
in interface GenericScanController
- Overrides:
close
in class BTreeScan
- Throws:
StandardException
- Standard exception policy.- See Also:
GenericScanController.newRowLocationTemplate()
closeForEndTransaction
public boolean closeForEndTransaction(boolean closeHeldScan)
throws StandardException
- Close the scan, a commit or abort is about to happen.
- Specified by:
closeForEndTransaction
in interface ScanManager
- Overrides:
closeForEndTransaction
in class BTreeScan
- 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.
- Throws:
StandardException
- Standard exception policy.
init
public void init(TransactionManager xact_manager,
Transaction rawtran,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level,
boolean open_for_locking,
FormatableBitSet scanColumnList,
B2I conglomerate,
B2IUndo undo)
throws StandardException
- Initialize the scan for use.
Any changes to this method may have to be reflected in close as well.
The btree init opens the container (super.init), and stores away the
state of the qualifiers. The actual searching for the first position
is delayed until the first next() call.
- Throws:
StandardException
- Standard exception policy.
Apache Derby V10.6 Internals - Copyright © 2004,2007 The Apache Software Foundation. All Rights Reserved.