A sliding window policy is implemented to manage database objects. At a first time, a first portion of a database object is allocated to a first tier of a multi-tier storage system. The first portion corresponds to a first specified percentage of the size of the database object at the first time and is selected according to information associated with the database object. The remaining portion of the database object at the first time is allocated to one or more other tiers. At a second (later) time, a second portion of the database object is allocated to the first tier. The second portion corresponds to a second specified percentage of the size of the database object at the second time and is also selected according to information associated with the database object. The remaining portion of the database object at the second time is allocated to the other tier(s).