RecordHandle

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org.apache.derby.iapi.store.raw
Interface RecordHandle

All Superinterfaces:: org.apache.derby.iapi.services.locks.Lockable

public interface RecordHandle
extends org.apache.derby.iapi.services.locks.Lockable

A handle to a record within a container. This interface does not provide an information about the data of the record, it is only used to perform updates, deletes and allow ordered record manipulation. MT - immutable

Field Summary

static int DEALLOCATE_PROTECTION_HANDLE
          A lock with this recordHandle protects this deallocated page from being freed and reallocated.

static int FIRST_RECORD_ID
          First recordId that is used to identify a record.

static int INVALID_RECORD_HANDLE
          An invalid record handle

static int PREVIOUS_KEY_HANDLE
          A lock with this recordHandle is used to lock the range of keys between the first key in a btree and keys previous to it.

static int RECORD_ID_PROTECTION_HANDLE
          A lock with this recordHandle protects all the recordIds in the page.

static int RESERVED4_RECORD_HANDLE
          Reserve for future use - name it and define it when you have a need to use one

static int RESERVED5_RECORD_HANDLE


Method Summary

ContainerKey getContainerId()
          Return the identity of my container.

int getId()
          Obtain the page-unique identifier for this record.

java.lang.Object getPageId()
          Return the identity of my Page.

long getPageNumber()
          Obtain the page number this record lives on.

int getSlotNumberHint()
          What slot number might the record be at?

Methods inherited from interface org.apache.derby.iapi.services.locks.Lockable

lockAttributes, lockerAlwaysCompatible, lockEvent, requestCompatible, unlockEvent

Field Detail

INVALID_RECORD_HANDLE

public static final int INVALID_RECORD_HANDLE

An invalid record handle

See Also:: Constant Field Values

RECORD_ID_PROTECTION_HANDLE

public static final int RECORD_ID_PROTECTION_HANDLE

A lock with this recordHandle protects all the recordIds in the page. No recordId can disappear while this lock is held. New recordIds may appear while this lock is held.

See Also:: Constant Field Values

DEALLOCATE_PROTECTION_HANDLE

public static final int DEALLOCATE_PROTECTION_HANDLE

A lock with this recordHandle protects this deallocated page from being freed and reallocated. This lock is released when the transaction that deallocated the page terminates, at which point the page can be freed if the transaction committed.

See Also:: Constant Field Values

PREVIOUS_KEY_HANDLE

public static final int PREVIOUS_KEY_HANDLE

A lock with this recordHandle is used to lock the range of keys between the first key in a btree and keys previous to it.

See Also:: Constant Field Values

RESERVED4_RECORD_HANDLE

public static final int RESERVED4_RECORD_HANDLE

Reserve for future use - name it and define it when you have a need to use one

See Also:: Constant Field Values

RESERVED5_RECORD_HANDLE

public static final int RESERVED5_RECORD_HANDLE

See Also:: Constant Field Values

FIRST_RECORD_ID

public static final int FIRST_RECORD_ID

First recordId that is used to identify a record.

See Also:: Constant Field Values

Method Detail

getId

public int getId()

Obtain the page-unique identifier for this record. This id combined with a page number is guaranteed to be unique within a container.

getPageNumber

public long getPageNumber()

Obtain the page number this record lives on.

getSlotNumberHint

public int getSlotNumberHint()

What slot number might the record be at?

The raw store guarantees that the record handle of a record will not change, but it's slot number may. An implementation of a record handle may provide a hint of the slot number, which may help routines like Page.getSlotNumber() perform better.

If an implementation does not track slot numbers at all the implementation should just always return Page.FIRST_SLOT_NUMBER.

getContainerId

public ContainerKey getContainerId()

Return the identity of my container.

getPageId

public java.lang.Object getPageId()

Return the identity of my Page.