Applications of Linear Lists for Sequential Access

The mechanism of the Counter Scheme (CS) has been shown to be an effective statistical approach for the reorganization of linear lists, where the records in the list are referenced independently with a time homogeneous multinomial distribution. In this paper we show that derivative schemes can be used effectively in other contexts as well. Specifically, we consider (a) linear lists that are doubly linked, so that they may be accessed at both ends, (b) multilists, which result from dissecting a linear list into several pieces that are accessed independently and reside in WORM (write-once-read-many) store, and (c) reorganizing a disk, by copying its contents to another disk, so as to minimize the expected seek time required to access a record.

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A representation for linear lists with movable fingers

10.1145/800133.804328 ◽

1978 ◽

Cited By ~ 7

Author(s):

Mark R. Brown ◽

Robert E. Tarjan

Keyword(s):

Linear Lists

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The Move-to-Front Rule for Multiple Lists

Probability in the Engineering and Informational Sciences ◽

10.1017/s0269964800001431 ◽

1990 ◽

Vol 4 (1) ◽

pp. 19-27 ◽

Cited By ~ 1

Author(s):

Costas Courcoubetis ◽

Richard R. Weber

Keyword(s):

Simple Form ◽

Random Variables ◽

Independent Random Variables ◽

Single List ◽

The Cost ◽

Linear Lists

A number of data items (1,2,…,n) are to be maintained in a structure which consists of several linear lists. Successive requests to access items are independent random variables, and the probability that a particular request is for item i is pi. The cost of accessing the jth item from the front of a list is j. For a single list, the move-to-front rule (MF) has been extensively studied and has been shown to provide good performance. In some actual circumstances, MF is the only physically realizable or convenient policy. We extend the study of move-to-front by examining the case where items are kept in several lists. Following its access, an item must be replaced at the front of one of the lists. In certain cases, assuming the pi's are known, the policy which minimizes the average retrieval cost takes a particularly simple form: no item is ever moved from the list in which it is placed initially.

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