Union All will include duplicates. Union will remove duplicates:
proc sql; create table table1 as select obs2,obs4 from table2 union select obs2,obs4 from table3 union select obs2,obs4 from table4;
Ready to join fellow brilliant minds for the SAS Hackathon?
Build your skills. Make connections. Enjoy creative freedom. Maybe change the world. Registration is now open through August 30th. Visit the SAS Hackathon homepage.