Sign In

Communications of the ACM

Communications of the ACM

Packed scatter tables

Scatter tables for open addressing benefit from recursive entry displacements, cutoffs for unsuccessful searches, and auxiliary cost functions. Compared with conventional methods, the new techniques provide substantially improved tables that resemble exact-solution optimal packings. The displacements are depth-limited approximations to an enumerative (exhaustive) optimization, although packing costs remain linear—O(n)—with table size n. The techniques are primarily suited for important fixed (but possibly quite large) tables for which reference frequencies may be known: op-code tables, spelling dictionaries, access arrays. Introduction of frequency weights further improves retrievals, but the enhancement may degrade cutoffs.

The full text of this article is premium content


No entries found

Log in to Read the Full Article

Sign In

Sign in using your ACM Web Account username and password to access premium content if you are an ACM member, Communications subscriber or Digital Library subscriber.

Need Access?

Please select one of the options below for access to premium content and features.

Create a Web Account

If you are already an ACM member, Communications subscriber, or Digital Library subscriber, please set up a web account to access premium content on this site.

Join the ACM

Become a member to take full advantage of ACM's outstanding computing information resources, networking opportunities, and other benefits.

Subscribe to Communications of the ACM Magazine

Get full access to 50+ years of CACM content and receive the print version of the magazine monthly.

Purchase the Article

Non-members can purchase this article or a copy of the magazine in which it appears.
Sign In for Full Access
» Forgot Password? » Create an ACM Web Account