Computing Reviews
Today's Issue Hot Topics Search Browse Recommended My Account Log In
Review Help
Search
Self-organizing search lists using probabilistic back-pointers
Hester J., Hirschberg D. Communications of the ACM30 (12):1074-1079,1987.Type:Article
Date Reviewed: Oct 1 1988

Self-organizing search lists are linearly linked lists in which more frequently accessed records are moved forward. The literature has discussed the move to front, which approaches steady state quickly; the transpose, in which the record only moves ahead one record, which has a slower convergence rate but a smaller average cost per record access once steady state is reached; and move ahead k, which is a compromise. The authors first meld and generalize these record manipulation techniques into one algorithm by using a Boolean jump function that is evaluated at each probe. If jump is set to true, a back pointer b is set to the position of the current record. Once the requested key is found it is reinserted in front of the record that b points to.

The authors point out that when reinsertions are done at fixed distances, as in the three techniques above, cost analyses are difficult. This is because the cumulative effect of reinsertions makes the distance searched non-independent. This leads them to suggest a probabilistic jump distance function. The major benefit as I see it is to allow analysis, not to improve performance.

Reviewer:  T. Brown Review #: CR112440
Bookmark and Share
 
Lists, Stacks, And Queues (E.1 ... )
 
 
Probabilistic Algorithms (Including Monte Carlo) (G.3 ... )
 
 
Sorting And Searching (F.2.2 ... )
 
Would you recommend this review?
yes
no
Other reviews under "Lists, Stacks, And Queues": Date
A priority queue for the all pairs shortest path problem
Moffat A., Takaoka T. Information Processing Letters 18(4): 189-193, 1984. Type: Article
Mar 1 1985
Amortized efficiency of list update and paging rules
Sleator D., Tarjan R. (ed) Communications of the ACM 28(2): 202-208, 1985. Type: Article
Nov 1 1985
Self-organizing linear search
Hester J., Hirschberg D. ACM Computing Surveys 17(3): 295-311, 1985. Type: Article
Sep 1 1986
more...

E-Mail This Printer-Friendly
Send Your Comments
Contact Us
Reproduction in whole or in part without permission is prohibited.   Copyright 1999-2024 ThinkLoud®
Terms of Use
| Privacy Policy