Improving the Access Time for Random Access Files Clustering in the key set is decreased by smoothing the key-to-address transformation, and by adding shadow buckets to an open chaining file. The keys are pre-hashed before the address division, to remove the effect of sequential properties in the key set. Shadow buckets in the key search sequence reduce the effect of nonuniformity in file loading, and decrease the number of maximum probes needed to locate a record. The combined effects of these techniques lead to improved file performance for secondary storage devices, as shown by empirical studies. CACM March, 1977 Clapson, P. hashing, hashing techniques, hashing methods, hash coding, keys, key transformation, key-to-address transformation, direct addressing, direct access, direct access method, randomizing, random access, file addressing, file organizations, file structures, scatter storage, search method, collisions, synonyms, clustering, information retrieval, open addressing, open chaining, buckets, bucket size, shadow buckets, combinatorics 3.7 3.72 3.73 3.74 4.9 5.39 CA770301 JB December 30, 1977 2:00 AM 1676 4 2991 1682 4 2991 1728 4 2991 1860 4 2991 1973 4 2991 1973 4 2991 1992 4 2991 2018 4 2991 2032 4 2991 2033 4 2991 2107 4 2991 2109 4 2991 2138 4 2991 2203 4 2991 2203 4 2991 2251 4 2991 2251 4 2991 2258 4 2991 2319 4 2991 2313 4 2991 2359 4 2991 2359 4 2991 2437 4 2991 2524 4 2991 2530 4 2991 2537 4 2991 2543 4 2991 2543 4 2991 2552 4 2991 2552 4 2991 2559 4 2991 2559 4 2991 2573 4 2991 2781 4 2991 2860 4 2991 2991 4 2991 2991 4 2991 2991 4 2991 3053 4 2991 3053 4 2991 3083 4 2991 1785 5 2991 2107 5 2991 2203 5 2991 2991 5 2991 2991 5 2991 2991 5 2991