Abstract: The invention relates to a database system comprising a plurality of stations (101, 102, . . . , 10n) communicating with one another. The data that is inserted or updated in an originating station is backed up in at least one other station referred to as a “receiving” station. Means are provided so that data of a determined kind can be backed up synchronously or asynchronously on another station depending on whether or not a pre-established criterion is satisfied. For example, data that is modified progressively is backed up asynchronously until the data has finished being modified, and is backed up synchronously once modification has been finished. Such data may be routing data in a telecommunications system.

Abstract: The method combines two known types of access: access by pointer and access by variable. These two types of access are made compatible by particular rules of managing the locks: "hold", "read lock", and "write lock". Application to software platforms, in particular those used for telecommunications systems.

Abstract: A method of isolating a memory location containing an obsolete value of a variable, in a shared memory of a computer, said location being referenced via a pointer for access in the context of a first transaction, a lock called a "hold" being placed on said location and being assigned to a single task, said hold preventing any other task from accessing said location. The method of the invention does not free the location containing the obsolete value, but it isolates it from transactions other than that transaction which possesses the first pointer. This allows the task owning the first pointer to continue to access said obsolete value. However, any transaction can access another value of the variable, without waiting, because the descriptor of said variable directs said transactions to a location which is freely accessible and contains said other value.