Module 5: Disk-based Index Structures
  Lecture 23: X-tree
 

                                           

 

 

Deletion, searching and performance
  • Underflow of supernodes may create normal nodes
  • When both pages need to be accessed, -tree reduces the cost by putting them sequentially rather than random I/O
  • Factor of speed-up over R*-tree is high for higher dimensions
  • Combination of efficient behavior of
 
  • R*-trees in low dimensions
 
  • Sequential scan in high dimensions
  • Still does not scale well for very high dimensions in comparison to sequential scan