Timestamped data

Timestamping is a technique for representing multiple versions of the same source data within one database. The source data must include dates (VALID_START and VALID_END columns) that can be used to determine the period for which each record is valid. This enables the Oracle Empirica Signal application to reconstruct data for different periods of time. As a result, you can base data mining runs, queries, and case series on source data as of a date that you specify. This date is referred to as the As Of date.

In the data mining run, query, or case series, data is used if the following is true:

VALID_START (if present) <= Specified As Of Date < VALID_END (if present)

For example, suppose that the source data includes the following DRUGS table, where an edit occurred for case ID 100:

CASE_ID	DRUG	ROUTE	VALID_START	VALID_END
100	DrugA	IV	01-01-2005	06-01-2005
100	DrugA	ORAL	06-01-2005	No end date

• If a run is performed as of 2/1/2005, the Route for DrugA is IV.
• If a run is performed as of 7/1/2005, the Route for DrugA is ORAL.
• If a run is performed as of 6/1/2005, the Route for DrugA is ORAL.

Specifying an As Of date

On pages where you specify an As Of date, a default date appears. You can change the date to another date that is within the range determined by the source description table for the data configuration.