A method and a telecommunication database system for facilitating modifications in the database and the handling of data queries. The database comprises an original dataset with data entries containing original data for different objects, and at least one auxiliary dataset with data entries containing updated data for at least some of the objects. A dataset tag is included in the data entries in either dataset indicating which dataset each entry belongs to. When a querying logic makes a query for data in a wanted data entry, the wanted data entry is obtained from a dataset determined based on the dataset tag in the data entry.