org.apache.derby.impl.store.access.btree.index
Class B2IForwardScan
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.BTreeForwardScan
org.apache.derby.impl.store.access.btree.index.B2IForwardScan
- All Implemented Interfaces:
- ScanManager, GenericScanController, GroupFetchScanController, RowCountable, ScanController
public class B2IForwardScan
- extends BTreeForwardScan
The btree secondary index implementation of ScanManager which provides reading
and deleting of entries in the btree secondary index.
This supports setting up and
iterating through a set of rows while providing a start key, stop key,
and a set of AND and OR qualifiers to skip unwanted rows. Currently
derby only supports forward scans (but individual columns can have
descending order). This interface is also used to delete rows from
the conglomerate. Note that update is not supported, it must be
implemented as a delete, followed by an insert.
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,
boolean hold,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level,
boolean open_for_locking,
FormatableBitSet scanColumnList,
DataValueDescriptor[] startKeyValue,
int startSearchOperator,
Qualifier[][] qualifier,
DataValueDescriptor[] stopKeyValue,
int stopSearchOperator,
B2I conglomerate,
B2IUndo undo,
B2IStaticCompiledInfo static_info,
DynamicCompiledOpenConglomInfo dynamic_info)
Initialize the scan for use. |
ContainerHandle |
reopen()
Open the container after it has been closed previously. |
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, 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
init_isolation_level
private int init_isolation_level
B2IForwardScan
B2IForwardScan()
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.
reopen
public ContainerHandle reopen()
throws StandardException
- Open the container after it has been closed previously.
Open the container, obtaining necessary locks. Most work is actually
done by RawStore.openContainer(). Will only reopen() if the container
is not already open.
- Overrides:
reopen
in class OpenBTree
- Throws:
StandardException
- Standard exception policy.
init
public void init(TransactionManager xact_manager,
Transaction rawtran,
boolean hold,
int open_mode,
int lock_level,
LockingPolicy locking_policy,
int isolation_level,
boolean open_for_locking,
FormatableBitSet scanColumnList,
DataValueDescriptor[] startKeyValue,
int startSearchOperator,
Qualifier[][] qualifier,
DataValueDescriptor[] stopKeyValue,
int stopSearchOperator,
B2I conglomerate,
B2IUndo undo,
B2IStaticCompiledInfo static_info,
DynamicCompiledOpenConglomInfo dynamic_info)
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.