A heuristic approach to vertical fragmentation incorporating query information

Fragmentation, allocation and replication are database distribution design techniques that aim at improving the system performance. Among the two fragmentation techniques, vertical fragmentation is often considered more complicated than horizontal fragmentation, because the huge number of alternatives makes it nearly impossible to obtain an optimal solution to the vertical fragmentation problem. Therefore, we can only expect to find out a heuristic solution. Often fragmentation and allocation are considered separately, disregarding that they are using the same input information to achieve the same objective, i.e. improve the overall system performance. This paper addresses vertical fragmentation and allocation simultaneously in the context of the relational model. The core of the paper is a heuristic approach to vertical fragmentation, which uses a cost model and is targeted at globally minimising these costs