Editing Distributed hash table (section)

==== Locality-preserving hashing ====
{{further|Locality-preserving hashing}}

Locality-preserving hashing ensures that similar keys are assigned to similar objects. This can enable a more efficient execution of range queries, however, in contrast to using consistent hashing, there is no more assurance that the keys (and thus the load) is uniformly randomly distributed over the key space and the participating peers. DHT protocols such as Self-Chord and Oscar<ref>{{Cite journal|last1=Girdzijauskas|first1=Šarūnas|last2=Datta|first2=Anwitaman|last3=Aberer|first3=Karl|date=2010-02-01|title=Structured overlay for heterogeneous environments|journal=ACM Transactions on Autonomous and Adaptive Systems|volume=5|issue=1|pages=1–25|doi=10.1145/1671948.1671950|s2cid=13218263|issn=1556-4665|url=http://infoscience.epfl.ch/record/134972|access-date=2020-03-12|archive-date=2020-07-12|archive-url=https://web.archive.org/web/20200712230838/https://infoscience.epfl.ch/record/134972|url-status=live}}</ref> address such issues. Self-Chord decouples object keys from peer IDs and sorts keys along the ring with a statistical approach based on the [[swarm intelligence]] paradigm.<ref>{{cite journal |last1=Forestiero |first1=Agostino |last2=Leonardi |first2=Emilio |last3=Mastroianni |first3=Carlo |last4=Meo |first4=Michela |title=Self-Chord: A Bio-Inspired P2P Framework for Self-Organizing Distributed Systems |journal=IEEE/ACM Transactions on Networking |date=October 2010 |volume=18 |issue=5 |pages=1651–1664 |doi=10.1109/TNET.2010.2046745 |s2cid=14797120 |url=http://porto.polito.it/2370172/ |access-date=2019-07-28 |archive-date=2012-07-01 |archive-url=https://web.archive.org/web/20120701163158/http://porto.polito.it/2370172/ |url-status=live }}</ref> Sorting ensures that similar keys are stored by neighbour nodes and that discovery procedures, including [[Range query (data structures)|range queries]], can be performed in logarithmic time. Oscar constructs a navigable [[small-world network]] based on [[random walk]] sampling also assuring logarithmic search time.