1. A method of performing a calculation on objects of a database, comprising: at a plurality of local servers: opening a subset of the objects, performing the calculation on the subset to generate intermediate results therefrom, and closing the objects; at a central server, generating final results of the calculation from the intermediate results obtained by the local servers; and at the plurality of local servers, opening objects for which the final results are relevant, writing the final results to the relevant objects, and closing the relevant objects.