Insert-only or append-only describes how data is managed when inserting new data. The principle idea of insert-only is that changes to existing data are handled by appending new tuples to the data storage. In other words, the database does not allow applications to perform updates or deletions on physically stored tuples of data. This design approach allows the introduction of a specific write-optimized data store for fast writing and a read-optimized data store for fast reading.Traditional database systems support four operations for data manipulations, i.e. inserting new data, selecting data, delete data, and updating data. The latter two are considered as destructive since original data is no longer available after its execution. In other words, it is neither possible to detect nor to reconstruct all values for a certain attribute; only the latest value is available. Insert-only enables storing the complete history of value changes and the latest value for a certain attribute. For instance, this is also a foundation of all bookkeeping systems to guarantee transparency. For the history-based access control, insert-only builds the basis to store the entire history of queries for access decision. In addition, insert-only enables tracing of access decision, which can be used to perform incident analysis. Please also see our podcast on this technology concept.