org.h2.index
Class PageBtreeNode

java.lang.Object
  org.h2.util.CacheObject
      org.h2.store.Record
          org.h2.store.Page
              org.h2.index.PageBtree
                  org.h2.index.PageBtreeNode

public class PageBtreeNode
extends PageBtree

A b-tree node page that contains index data. Format:

• page type: byte
• checksum: short
• parent page id (0 for root): int
• index id: varInt
• count of all children (-1 if not known): int
• entry count: short
• rightmost child page id: int
• entries (child page id: int, offset: short) The row contains the largest key of the respective child, meaning row[0] contains the largest key of child[0].

  Field Summary

  Fields inherited from class org.h2.index.PageBtree

  data, entryCount, index, offsets, onlyPosition, parentPageId, rows, start, written

  Fields inherited from class org.h2.store.Page

  FLAG_LAST, TYPE_BTREE_LEAF, TYPE_BTREE_NODE, TYPE_DATA_LEAF, TYPE_DATA_NODE, TYPE_DATA_OVERFLOW, TYPE_EMPTY, TYPE_FREE_LIST, TYPE_STREAM_DATA, TYPE_STREAM_TRUNK

  Fields inherited from class org.h2.util.CacheObject

  blockCount, cacheQueue, chained, next, previous

  Method Summary

  int	getByteCount(DataPage dummy) Get the number of bytes required for the data if the given data page would be used.
  void	moveTo(Session session, int newPos) Copy the data to a new location, change the parent to point to the new location, and free up the current page.
  static Page	read(PageBtreeIndex index, Data data, int pageId) Read a b-tree node page.
  protected void	remapChildren() Update the parent id of all children.
  java.lang.String	toString()
  void	write(DataPage buff) Write the record to the data page.

  Methods inherited from class org.h2.index.PageBtree

  getMemorySize, readAllRows

  Methods inherited from class org.h2.store.Record

  canRemove, commit, getSessionId, getStorageId, isDeleted, isEmpty, isLogWritten, prepareWrite, setDeleted, setLastLog, setLogWritten, setSessionId, setStorageId

  Methods inherited from class org.h2.util.CacheObject

  getBlockCount, getPos, isChanged, isPinned, setBlockCount, setChanged, setPos, sort

  Methods inherited from class java.lang.Object

  clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

  Method Detail

  read

  public static Page read(PageBtreeIndex index,
                          Data data,
                          int pageId)
                   throws java.sql.SQLException

  Read a b-tree node page.

  Parameters:

  index - the index

  data - the data

  pageId - the page id

  Returns:

  the page

  Throws:

  java.sql.SQLException

  remapChildren

  protected void remapChildren()
                        throws java.sql.SQLException

  Description copied from class: PageBtree

  Update the parent id of all children.

  Throws:

  java.sql.SQLException

  getByteCount

  public int getByteCount(DataPage dummy)

  Description copied from class: Record

  Get the number of bytes required for the data if the given data page would be used.

  Specified by:

  getByteCount in class Record

  Parameters:

  dummy - the template data page

  Returns:

  the number of bytes

  write

  public void write(DataPage buff)
             throws java.sql.SQLException

  Description copied from class: Record

  Write the record to the data page.

  Specified by:

  write in class Record

  Parameters:

  buff - the data page

  Throws:

  java.sql.SQLException

  toString

  public java.lang.String toString()

  Overrides:

  toString in class java.lang.Object

  moveTo

  public void moveTo(Session session,
                     int newPos)
              throws java.sql.SQLException

  Description copied from class: Page

  Copy the data to a new location, change the parent to point to the new location, and free up the current page.

  Specified by:

  moveTo in class Page

  Parameters:

  session - the session

  newPos - the new position

  Throws:

  java.sql.SQLException