The Tracer tool is used to display information about when a load activity starts and about each reference to a data page. To view declarative processing (by your own requestor session) with the Tracer tool:
Click the Tracer in the developer toolbar in Dev Studio or type
CTRL+Tto start the Tracer.
Click Options to open the Options window.
Select any rulesets, in the Event field enter "Data Pages", and click Add.
Click OK to close the Options window.