Summary: I/O-efficient Point Location using Persistent B-Trees
Department of Computer Science
We present an external planar point location data structure
that is I/O-efficient both in theory and practice.
The developed structure uses linear space and answers a
query in optimal O(logB N) I/Os, where B is the disk block
size. It is based on a persistent B-tree, and all previously de-
veloped such structures assume a total order on the elements
in the structure. As a theoretical result of independent
interest, we show how to remove this assumption.
Most previous theoretical I/O-efficient planer point loca-
tion structures are relatively complicated and have not been
implemented. Based on a bucket approach, Vahrenhold and
Hinrichs therefore developed a simple and practical, but
theoretically non-optimal, heuristic structure. We present