Finding Orphans

I have a situation whereby I am trying to determine the number of orphans in an addresses table by checking for those address keys NOT IN the five tables which use it, to wit:

SELECT count(*)
  FROM address
 WHERE addr_key NOT IN (SELECT addr_key

                          FROM client)
   AND addr_key NOT IN (SELECT addr_key
                          FROM employee)
   AND addr_key NOT IN (SELECT addr_key
                          FROM groups)
   AND addr_key NOT IN (SELECT addr_key
                          FROM patient)
   AND addr_key NOT IN (SELECT addr_key
                          FROM provider)

These tables contain anywhere from a few hundred to a few million rows and only the address and patient tables have an index on the addr_key column. After running three hours the query returns a zero count which I know is NOT correct.

After pulling hair (and I don't have that much left to pull!), I still cannot see what I am missing. Any ideas? Is there a better way to do this?

Thank you,
Lucky

Lucky Leavell                      Phone: (800) 481-2393 or (812) 366-4066
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