Abstract: During operation of a computer system, index records and data records of a data structure are organized in a hierarchical manner, with index records being at a higher level of the hierarchy than the data records referenced by the index records. While the data structure is manipulated, the data records are stored in a random access memory. Modifications made to the data structure are chronologically written to a disk storage in a bottom-first/top-last order of the hierarchy for persistent storage as a database. A back-up copy of the database is made by storing the data and index records of the database in a top-first/bottom-last order on a sequentially readable media. A temporal and spatial view of a portion of the database can be obtained by accessing the index records and the data records of the database or the back-up media in the top-first/bottom last order.