The quality of database distribution design, which involves fragmentation and allocation, should be assessed by the performance of a system. In particular, this applies to non-relational database systems. This paper addresses fragmentation and allocation in the context of complex value databases. Fragmentation and fragment allocation are performed simultaneously. For this we present a query processing cost model to evaluate the performance of the system. The core of the paper is a heuristic approach for fragmentation and fragment allocation, which uses the cost model and is targeted at globally minimising these costs. The validity of the approach is supported by experimental results.