Prune days in DAC

• DAC stores a value called LAST_REFRESH_DATE at the end of an ETL extract.
• During the next run, DAC captures changes to the source data by comparing this LAST_REFRESH_DATE with the LAST_UPD date of records in the source.
• So if the LAST_REFRESH_DATE is less than LAST_UPD of a source record, then the record being processed has either been updated or created between the time of last execution and the current run
• But what will happen if a record in the source is committed between the time of starting the data extract and completing the extract with a commit date that is less than the LAST_REFRESH_DATE

Prune days to the rescue!!! The solution to the above problem is to set the PRUNE_DAYS parameter.

If the prune days parameter is set to 1 for example, the change capture process will use LAST_REFRESH_DATE – Prune days as the cutoff timestamp for change capture