 segment.  Deleting a record implies: 
 
      1) All column entries in the record are deleted. 
 
      2) Link counts are decremented for data pages containing 
         column entries in the record to be deleted.  Pages whose 
         link counts drop to zero are freed. 
 
      3) All column indexes are updated for the parent segment. 
 
      4) The link count is decremented for the page containing the 
         record pointer structure of the record to be deleted.  If 
         the link count drops t