### Abstract

The technique of speeding up access into search structures by maintaining fingers that point to various locations of the search structure is considered. The problem of choosing, in a large search structure, locations at which to maintain fingers is treated. In particular, a server problem in which k servers move along a line segment of length m, where m is the number of keys in the search structure, is addressed. Since fingers may be arbitrarily copied, a server is allowed to jump, or fork, to a location currently occupied by another server. Online algorithms are presented and their competitiveness analyzed. It is shown that the case in which k = 2 behaves differently from the case in which k ≥ 3, by showing that there is a four-competitive algorithm for k = 2 that never forks its fingers. For k ≥ 3, it is shown that any online algorithm that does not fork its fingers can be at most Ω(m^{1/2})-competitive. The main result is that for k = 3 there is an online algorithm that forks and is constant competitive (independent of m, the size of the search structure). The algorithm is simple and implementable.

Original language | English (US) |
---|---|

Pages (from-to) | 480-489 |

Number of pages | 10 |

Journal | Annual Symposium on Foundations of Computer Science - Proceedings |

Volume | 2 |

State | Published - Dec 1 1990 |

Event | Proceedings of the 31st Annual Symposium on Foundations of Computer Science - St. Louis, MO, USA Duration: Oct 22 1990 → Oct 24 1990 |

### ASJC Scopus subject areas

- Hardware and Architecture

### Cite this

*Annual Symposium on Foundations of Computer Science - Proceedings*,

*2*, 480-489.