Organization and maintenance of large ordered indexes
- 610 Downloads
Organization and maintenance of an index for a dynamic random access file is considered. It is assumed that the index must be kept on some pseudo random access backup store like a disc or a drum. The index organization described allows retrieval, insertion, and deletion of keys in time proportional to logkI where I is the size of the index and k is a device dependent natural number such that the performance of the scheme becomes near optimal. Storage utilization is at least 50% but generally much higher. The pages of the index are organized in a special datastructure, so-called B-trees. The scheme is analyzed, performance bounds are obtained, and a near optimal k is computed. Experiments have been performed with indexes up to 100000 keys. An index of size 15000 (100000) can be maintained with an average of 9 (at least 4) transactions per second on an IBM 360/44 with a 2311 disc.
KeywordsInformation System Operating System Data Structure Communication Network Information Theory
Unable to display preview. Download preview PDF.
- 1.Adelson-Velskii, G. M., Landis, E. M.: An information organization algorithm. DANSSSR, 146, 263–266 (1962).Google Scholar
- 2.Foster, C. C.: Information storage and retrieval using AVL trees. Proc. ACM 20th Nat'1. Conf. 192–205 (1965).Google Scholar
- 3.Landauer, W. I.: The balanced tree and its utilization in information retrieval. IEEE Trans. on Electronic Computers, Vol. EC-12, No. 6, December 1963.Google Scholar
- 4.Sussenguth, E. H., Jr.: The use of tree structures for processing files. Comm. ACM, 6, No. 5, May 1963.Google Scholar