Thanks Matthew that worked great. What a great forum this is: I am learning a lot! PS. I am now running both solutions on two similar computers. Let's see which is fastest. -- View this message in context: http://r.789695.n4.nabble.com/Re-Transforming-relational-data-tp3307449p3321214.html Sent from the R help mailing list archive at Nabble.com.