Quite true, but basically unrelated to the number of BY variables.

On Wed, 30 Apr 2003 10:12:19 -0700, Biff Canlett <Biff@CANLETT.COM> wrote:

>If you are new to SAS merges, it is very important that you study and >understand the results of many to many matches. These may not be what >you expect. The result will not be the Cartesian product you would >get from SQL. > >eseele@STATE.PA.US (Seele, Eric) wrote in message news:<FDD36BBB99B1BF4D91C2E68E5AF26FF1A615C@hbgpri36.pa.lcl>... >> Greetings fellow SAS aficionados! >> >> Recently I came across a Merge statement with an accompanying By statement. >> This particular By statement was new to me, in that it listed not one, but >> two variables. I seek to find out what exactly happens when a data set is >> formed as the result of the merging of two data sets by two variables. How >> do I interpret the results of the merge? Does it matter what order the >> variables appear in the By statement? Any help that you are able to provide >> will be appreciated and should be sent to eseele@state.pa.us. >> >> Eric Seele >> Eric Seele >> >> Center for Workforce Information and Analysis >> Pennsylvania Department of Labor and Industry >> (717) 772-1707 >> eseele@state.pa.us