CURRENT REFRESH AGE special register

The CURRENT REFRESH AGE special register specifies a timestamp duration value with a data type of DECIMAL(20,6). It is the maximum duration since a particular timestamped event occurred to a cached data object (for example, a REFRESH TABLE statement processed on a system-maintained REFRESH DEFERRED materialized query table), such that the cached data object can be used to optimize the processing of a query. If CURRENT REFRESH AGE has a value of 99 999 999 999 999, and the query optimization class is 5 or more, the types of tables specified in CURRENT MAINTAINED TABLE TYPES FOR OPTIMIZATION are considered when optimizing the processing of a dynamic SQL query.

The value of CURRENT REFRESH AGE must be 0 or 99 999 999 999 999. The initial value is 0. The value can be changed by invoking the SET CURRENT REFRESH AGE statement.