A database structure that may be used for semistructured databases assigns each node of a database to a collection. For each collection, create rights, retrieve rights, associate rights and dissassociate rights are provided to one or more users, the rights being assigned in common for all nodes of the collection. Users can only carry out the task if they have the appropriate rights. In this way, a flexible database security structure is provided that can deliver appropriate security for different elements of a semistructured database.