The PREFILTERED parameter refers to filtered audit files generated by the Tanker Accessory.
PREFILTERED option
Description
FALSE NONE
DBEngine will not use prefiltered audit files.
TRUE ONLY
DBEngine will use only prefiltered audit files.
PREFERRED OPTIONAL
DBEngine will use prefiltered audit files if they are available. If they are not available, DBEngine automatically switches to using the original, unfiltered audit files.