I remembered that @Harsh recently put together a great list of resources and approaches for handling this problem.
Creating a report to list possible duplicates - #3 by Harsh
Along the same lines, @Greg’s post got me thinking - there’s likely a 90 second solution to this problem- in PQ do a GROUPBY on the fields that together define a duplicate and set the resulting column to count. Anything with a count > 1 is a duplicate.
- Brian