Expiration of historical databases
David Toman · 2002
We present a technique for automatic expiration of data in a historical data warehouse that preserves answers to a known and fixed set of first-order queries. In addition, we show that for queries with output size bounded by a function of the active data domain size (the number of values that have ever appeared in the warehouse), the size of the portion of the data warehouse history needed to answer the queries is also bounded by a function of the active data domain size and therefore does not depend on the age of the warehouse (the length of the history).