Implementing an Aging Policy in Your Tables

You can define an aging policy for one or more tables in your database.

An aging policy refers to the type of aging and the aging attributes, as well as the aging state (ON or OFF). You can specify one of the following types of aging policies: usage-based or time-based. Usage-based aging removes least recently used (LRU) data within a specified database usage range. Time-based aging removes data based on the specified data lifetime and frequency of the aging process. You can define only one type of aging for a specified table.

You can define an aging policy for a new table with the CREATE TABLE statement. You can add an aging policy to an existing table with the ALTER TABLE statement if the table does not already have an aging policy defined. You can change the aging policy by dropping aging and adding a new aging policy.

You cannot specify aging on the following types of tables:

• Global temporary tables

• Detail tables of materialized views

You can also implement aging in cache groups. See Implementing Aging in a Cache Group for TimesTen in Oracle TimesTen In-Memory Database Cache Guide.

This section includes the following topics:

• Usage-Based Aging

• Time-Based Aging

• Aging and Foreign Keys

• Scheduling When Aging Starts

• Aging and Replication

• Determining the Effectiveness of Aging