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Class btree.BTFileScan

java.lang.Object
   |
   +----btree.IndexFileScan
           |
           +----btree.BTFileScan

public class BTFileScan
extends IndexFileScan
implements GlobalConst
BTFileScan implements a search/iterate interface to B+ tree index files (class BTreeFile). It derives from abstract base class IndexFileScan.


Constructor Index

 o BTFileScan()

Method Index

 o delete_current()
Delete currently-being-scanned(i.e., just scanned) data entry.
 o DestroyBTreeFileScan()
destructor.
 o get_next()
Iterate once (during a scan).
 o keysize()
max size of the key

Constructors

 o BTFileScan
 public BTFileScan()

Methods

 o get_next
 public KeyDataEntry get_next()
Iterate once (during a scan).

Returns:
null if done; otherwise next KeyDataEntry
Overrides:
get_next in class IndexFileScan
 o delete_current
 public void delete_current()
Delete currently-being-scanned(i.e., just scanned) data entry.

Overrides:
delete_current in class IndexFileScan
 o keysize
 public int keysize()
max size of the key

Returns:
the maxumum size of the key in BTFile
Overrides:
keysize in class IndexFileScan
 o DestroyBTreeFileScan
 public void DestroyBTreeFileScan()
destructor. unpin some pages if they are not unpinned already. and do some clearing work.


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