Computational complexity of the file allocation problem in distributed database systems
Hiroshi Yamasaki, Tomio Hirata, Masaharu Imai, Toshihide Ibaraki · Systems and Computers in Japan · 1988
Abstract In most studies of the optimum allocation problem of the data file in the distributed database system, access to individual files is considered independent, ignoring the relation among files. This assumption may not be appropriate in actual cases. In this paper, the expression for the query cost is simplified as long as the essential aspect of the problem is maintained. A formulation is made based on a clear distinction between the part of the file which can be considered as independent in the individual access, and the part which is not. Then for each formulation, the computational complexity in the optimum file allocation is discussed. It is shown that the problem for the former can be answered in a polynomial time, while the latter is NP‐hard.