ABSTRACT
What is not included in the definition of ILM, but is critical to understanding ILM, is that every piece of data becomes fixed (i.e., read-only) at some time during its lifecycle-and that time is typically short compared to the full length of its lifecycle. Active changeable data reflects a creation and change process, where viewing the data at different times would reveal that the data had not stayed the same. At some point in time, however, this change ends. Even online transaction processing systems updating customer records create data that must be “frozen” after a certain period of time-say, at the end of the month or year, or after a certain event occurs. For example, when a hotel stay event has ended (and been paid for), the hotel reservation transaction has been completed and now is not subject to any further change (except perhaps error correction). That means that the information is fixed-content.
