java.lang.Object
- org.apache.derby.impl.store.access.btree.OpenBTree

Direct Known Subclasses:

BTreeController, BTreeCostController, BTreeScan
```
public class OpenBTree
extends java.lang.Object
```
An open b-tree contains fields and methods common to scans and controllers.
Concurrency Notes
An instance of an open b-tree is owned by a single context. The b-tree code assumes that the context ensures that only one thread at a time is using the open b-tree. The open b-tree itself does not enforce or check this.

Field Summary

Fields
Modifier and Type	Field	Description
`protected LogicalUndo`	`btree_undo`
`protected ContainerHandle`	`container`	The (open) container which contains the b-tree.
`protected long`	`err_containerid`	The conglomerate containerid for error reporting.
`private BTreeLockingPolicy`	`init_btree_locking_policy`	The Locking Policy to use for for access to this btree.
`private BTree`	`init_conglomerate`	The following group of fields are all basic input parameters which are provided by the calling code when doing any sort of operation requiring an open conglomerate (openScan(), open(), openCostController(), ...).
`private boolean`	`init_hold`
`protected int`	`init_lock_level`	Table or page locking?
`protected TransactionManager`	`init_open_user_scans`	The user transaction that opened this B-tree.
`private int`	`init_openmode`	The ContainerHandle mode the container is opened with.
`private Transaction`	`init_rawtran`
`private TransactionManager`	`init_xact_manager`	The TransactionManager that open'd this btree.
`protected OpenConglomerateScratchSpace`	`runtime_mem`	scratch space used for stuff like templates, export rows, ...

Constructor Summary

Constructors
Constructor Description

OpenBTree()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`checkConsistency()`	Check consistency of a btree.
`void`	`close()`	Close the open conglomerate.
`void`	`debugConglomerate()`	Dump information about tree into the log.
`boolean[]`	`getColumnSortOrderInfo()`
`BTree`	`getConglomerate()`
`ContainerHandle`	`getContainer()`
`ContainerHandle`	`getContainerHandle()`	Return the container handle.
`long`	`getEstimatedRowCount()`	Get the total estimated number of rows in the container.
`int`	`getHeight()`	get height of the tree.
`boolean`	`getHold()`
`BTreeLockingPolicy`	`getLockingPolicy()`
`int`	`getLockLevel()`
`int`	`getOpenMode()`
`Transaction`	`getRawTran()`
`OpenConglomerateScratchSpace`	`getRuntimeMem()`
`SpaceInfo`	`getSpaceInfo()`
`TransactionManager`	`getXactMgr()`	Public Accessors of This class:
`void`	`init(TransactionManager open_user_scans, TransactionManager xact_manager, ContainerHandle input_container, Transaction rawtran, boolean hold, int open_mode, int lock_level, BTreeLockingPolicy btree_locking_policy, BTree conglomerate, LogicalUndo undo, DynamicCompiledOpenConglomInfo dynamic_info)`	Initialize the open conglomerate.
`boolean`	`isClosed()`
`(package private) void`	`isIndexableRowConsistent(DataValueDescriptor[] row)`	Check if all the columns are Indexable and Storable.
`boolean`	`isTableLocked()`	is the open btree table locked?
`ContainerHandle`	`reopen()`	Open the container after it has been closed previously.
`void`	`setEstimatedRowCount(long count)`	Set the total estimated number of rows in the container.
`void`	`setLockingPolicy(BTreeLockingPolicy policy)`
`static boolean`	`test_errors(OpenBTree open_btree, java.lang.String debug_string, BTreeRowPosition pos, BTreeLockingPolicy btree_locking_policy, LeafControlRow leaf, boolean input_latch_released)`	Testing infrastructure to cause unusual paths through the code.

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

- Field Detail
  - init_conglomerate
```
private BTree init_conglomerate
```
    The following group of fields are all basic input parameters which are provided by the calling code when doing any sort of operation requiring an open conglomerate (openScan(), open(), openCostController(), ...). These are just saved values from what was initially input.
  - init_xact_manager
```
private TransactionManager init_xact_manager
```
    The TransactionManager that open'd this btree. In the case of Internal transactions used by split this will be the internal transaction, and init_open_user_scans will be the user transaction that began the internal transaction.
  - init_rawtran
```
private Transaction init_rawtran
```
  - init_openmode
```
private int init_openmode
```
    The ContainerHandle mode the container is opened with. Remember this so that if the BTree needs to do SMO with another transaction, it would open the container with the same mode.
  - init_lock_level
```
protected int init_lock_level
```
    Table or page locking?
  - init_hold
```
private boolean init_hold
```
  - init_btree_locking_policy
```
private BTreeLockingPolicy init_btree_locking_policy
```
    The Locking Policy to use for for access to this btree.
  - container
```
protected ContainerHandle container
```
    The (open) container which contains the b-tree.
  - err_containerid
```
protected long err_containerid
```
    The conglomerate containerid for error reporting.
  - init_open_user_scans
```
protected TransactionManager init_open_user_scans
```
    The user transaction that opened this B-tree.
  - btree_undo
```
protected LogicalUndo btree_undo
```
  - runtime_mem
```
protected OpenConglomerateScratchSpace runtime_mem
```
    scratch space used for stuff like templates, export rows, ...
- Constructor Detail
  - OpenBTree
```
public OpenBTree()
```
- Method Detail
  - getXactMgr
```
public final TransactionManager getXactMgr()
```
    Public Accessors of This class:
  - getRawTran
```
public final Transaction getRawTran()
```
  - getLockLevel
```
public final int getLockLevel()
```
  - getContainer
```
public final ContainerHandle getContainer()
```
  - getOpenMode
```
public final int getOpenMode()
```
  - getConglomerate
```
public final BTree getConglomerate()
```
  - getHold
```
public final boolean getHold()
```
  - getLockingPolicy
```
public final BTreeLockingPolicy getLockingPolicy()
```
  - setLockingPolicy
```
public final void setLockingPolicy(BTreeLockingPolicy policy)
```
  - isClosed
```
public final boolean isClosed()
```
  - getRuntimeMem
```
public final OpenConglomerateScratchSpace getRuntimeMem()
```
  - getEstimatedRowCount
```
public long getEstimatedRowCount()
                          throws StandardException
```
    Get the total estimated number of rows in the container.
    The number is a rough estimate and may be grossly off. In general the server will cache the row count and then occasionally write the count unlogged to a backing store. If the system happens to shutdown before the store gets a chance to update the row count it may wander from reality.
    This call is currently only supported on Heap conglomerates, it will throw an exception if called on btree conglomerates.
    
    Returns:
    
    The total estimated number of rows in the conglomerate.
    
    Throws:
    
    StandardException - Standard exception policy.
  - setEstimatedRowCount
```
public void setEstimatedRowCount(long count)
                          throws StandardException
```
    Set the total estimated number of rows in the container.
    Often, after a scan, the client of RawStore has a much better estimate of the number of rows in the container than what store has. For instance if we implement some sort of update statistics command, or just after a create index a complete scan will have been done of the table. In this case this interface allows the client to set the estimated row count for the container, and store will use that number for all future references.
    This call is currently only supported on Heap conglomerates, it will throw an exception if called on btree conglomerates.
    
    Parameters:
    
    count - the estimated number of rows in the container.
    
    Throws:
    
    StandardException - Standard exception policy.
  - checkConsistency
```
public void checkConsistency()
                      throws StandardException
```
    Check consistency of a btree.
    Read in root and check consistency of entire tree. Currently raises sanity check errors.
    RESOLVE (mikem) if this is to be supported in non-sanity servers what should it do?
    
    Throws:
    
    StandardException - Standard exception policy.
  - isTableLocked
```
public boolean isTableLocked()
```
    is the open btree table locked?
  - init
```
public void init(TransactionManager open_user_scans,
                 TransactionManager xact_manager,
                 ContainerHandle input_container,
                 Transaction rawtran,
                 boolean hold,
                 int open_mode,
                 int lock_level,
                 BTreeLockingPolicy btree_locking_policy,
                 BTree conglomerate,
                 LogicalUndo undo,
                 DynamicCompiledOpenConglomInfo dynamic_info)
          throws StandardException
```
    Initialize the open conglomerate.
    If container is null, open the container, otherwise use the container passed in. The container is always opened with no locking, it is up to the caller to make the appropriate container locking call.
    
    Parameters:
    
    open_user_scans - The user transaction which opened this btree.
    
    xact_manager - The current transaction, usually the same as "open_user_scans", but in the case of split it is the internal xact nested below the user xact.
    
    input_container - The open container holding the index, if it is already open, else null which will mean this routine will open it.
    
    rawtran - The current raw store transaction.
    
    open_mode - The opening mode for the ContainerHandle.
    
    conglomerate - Readonly description of the conglomerate.
    
    undo - Logical undo object to associate with all updates done on this open btree.
    
    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.
    
    Throws:
    
    StandardException - Standard exception policy.
  - close
```
public void close()
           throws StandardException
```
    Close the open conglomerate.
    
    Throws:
    
    StandardException
  - isIndexableRowConsistent
```
void isIndexableRowConsistent(DataValueDescriptor[] row)
                       throws StandardException
```
    Check if all the columns are Indexable and Storable. Eventually this routine could check whether all the types were right also.
    
    Throws:
    
    StandardException - Standard Exception Policy.
  - getContainerHandle
```
public ContainerHandle getContainerHandle()
```
    Return the container handle.
    
    Returns:
    
    The open container handle of the btree.
  - getHeight
```
public int getHeight()
              throws StandardException
```
    get height of the tree.
    Read in root and return the height (number of levels) of the tree. The level of a tree is 0 in the leaf and increases by 1 for each level of the tree as you go up the tree.
    
    Throws:
    
    StandardException - Standard exception policy.
  - debugConglomerate
```
public void debugConglomerate()
                       throws StandardException
```
    Dump information about tree into the log.
    Traverse the tree dumping info about tree into the log.
    
    Throws:
    
    StandardException - Standard exception policy.
  - test_errors
```
public static boolean test_errors(OpenBTree open_btree,
                                  java.lang.String debug_string,
                                  BTreeRowPosition pos,
                                  BTreeLockingPolicy btree_locking_policy,
                                  LeafControlRow leaf,
                                  boolean input_latch_released)
                           throws StandardException
```
    Testing infrastructure to cause unusual paths through the code.
    Through the use of debug flags allow test code to cause otherwise hard to cause paths through the code.
    
    Parameters:
    
    pos - the current scan position if the condition simulated by this call would have resulted in the position being saved
    
    Returns:
    
    whether the latch has been released by this routine.
    
    Throws:
    
    StandardException - Standard exception policy.
  - getSpaceInfo
```
public SpaceInfo getSpaceInfo()
                       throws StandardException
```
    Throws:
    
    StandardException
  - getColumnSortOrderInfo
```
public boolean[] getColumnSortOrderInfo()
                                 throws StandardException
```
    Throws:
    
    StandardException

Class OpenBTree

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

init_conglomerate

init_xact_manager

init_rawtran

init_openmode

init_lock_level

init_hold

init_btree_locking_policy

container

err_containerid

init_open_user_scans

btree_undo

runtime_mem

Constructor Detail

OpenBTree

Method Detail

getXactMgr

getRawTran

getLockLevel

getContainer

getOpenMode

getConglomerate

getHold

getLockingPolicy

setLockingPolicy

isClosed

getRuntimeMem

getEstimatedRowCount

setEstimatedRowCount

checkConsistency

isTableLocked

init

reopen

close

isIndexableRowConsistent

getContainerHandle

getHeight

debugConglomerate

test_errors

getSpaceInfo

getColumnSortOrderInfo