File organizations and access methods for CLV optical disks.File organizations and access methods for CLV optical disks. Πλήρης Δημοσίευση σε Συνέδριο Conference Full Paper 2015-10-051989enA large and important class of optical disc technology are CLV format discs such as CD ROM and WORM. In this paper, we exam- ine the issues related to the implementation and performance of several different file organizations on CLV format optical discs such as CD ROM and WORM. The organizations examined are based on hashing and trees. The CLV recording scheme is shown to be a good environment for efficiently implement- ing hashing. Single seek access and storage utili- zation levels approaching 100% can be achieved for CD ROM's It is shown that a B-tree organi- zation is not a good choice for WORM discs (both CAV and CLV), but a modified ISAM approach can be appropriate for WORM discs. We describe clustered BIM's, a class of tree organizations appropriate for CD ROMS. Expressions for the expected retrieval perfor- mance of both hashing and trees are also given. The paper concludes by outlining recent results and future directions on buffered imple- mentations of access methods for WORM discs, as well as advantages of signature based access methods for text retrieval in WORM disc archi- tectures. http://creativecommons.org/licenses/by/4.0/306-31412th International Conference on Research and Development in Information Retrieval Christodoulakis Stavros Χριστοδουλακης Σταυρος Daniel Alexander Ford Computer software--Refactoring Refactoring, Software software refactoring computer software refactoring refactoring software