On Competitive On-Line Paging with Lookahead

Abstract

This paper studies two methods for improving the competitive efficiency of on-line paging algorithms: in the first, the on-line algorithm canuse more pages; in the second, it is allowed to have a look-ahead, or inother words, some partial knowledge of the future. The paper considers anew measure for the look-ahead size as well as Young's resource-boundedlook-ahead and proves that both measures have the attractive propertythat the competitive efficiency of an on-line algorithm with k extra pagesand look-ahead l depends on k+l. Hence, under these measures, an on-linealgorithm has the same benefit from using an extra page or knowing anextra bit of the future