Thanks for the assistance. I agree with your take on using a/b/c as aliases, but I was tasked with "get it working, don't get it pretty". I thought that replacing an outer join with an "IN" was risky, but I think it's riskier to replace it with an "=", since, like you said, the query could return more than one result. I'll have to ask the business unit if that's by design, but is there not a way to maintain the join relationship?