https://communities.sas.com/t5/SAS-Procedures/minimize-memory-usage-of-MEANS-procedure/m-p/50123#M13632 Agreed. For large numbers of levels MEANS/SUMMARY using BY also runs a lot faster than using CLASS, at the expense of having to sort first. Thu, 14 Apr 2011 02:18:50 GMT SASKiwi 2011-04-14T02:18:50Z https://communities.sas.com/t5/SAS-Procedures/minimize-memory-usage-of-MEANS-procedure/m-p/50121#M13630 When attempting to minimize memory usage, the<BR /> most efficient way to do group processing when<BR /> using the MEANS procedure is to use:<BR /> A.<BR /> the BY statement.<BR /> B.<BR /> GROUPBY with the NOTSORTED specification.<BR /> C.<BR /> the CLASS statement.<BR /> D.<BR /> multiple WHERE statements.<BR /> <BR /> Which is the best answer? A or C? Thanks. Wed, 13 Apr 2011 21:13:37 GMT https://communities.sas.com/t5/SAS-Procedures/minimize-memory-usage-of-MEANS-procedure/m-p/50121#M13630 richard_hu2003 2011-04-13T21:13:37Z https://communities.sas.com/t5/SAS-Procedures/minimize-memory-usage-of-MEANS-procedure/m-p/50122#M13631 I choose A. Is it right?<BR /> <BR /> <BR /> Ksharp Thu, 14 Apr 2011 01:57:55 GMT https://communities.sas.com/t5/SAS-Procedures/minimize-memory-usage-of-MEANS-procedure/m-p/50122#M13631 Ksharp 2011-04-14T01:57:55Z https://communities.sas.com/t5/SAS-Procedures/minimize-memory-usage-of-MEANS-procedure/m-p/50123#M13632 Agreed. For large numbers of levels MEANS/SUMMARY using BY also runs a lot faster than using CLASS, at the expense of having to sort first. Thu, 14 Apr 2011 02:18:50 GMT https://communities.sas.com/t5/SAS-Procedures/minimize-memory-usage-of-MEANS-procedure/m-p/50123#M13632 SASKiwi 2011-04-14T02:18:50Z