In one aspect, a method for operating databases with a plurality of first data is provided. A temporary copy of at least some logically related parts of the plurality of first data is generated as second data for an editing procedure. The second data is offered by a user such that he can edit the second data. On conclusion of the editing procedure an individual comparison of the second data with the first data is performed such that when a second datum of the second data matches a first datum of the first data, a reference is created in the database to the first datum corresponding to the second datum. At least some of the second data for which no match with first data is determined is saved in the database.