text: --server core when running merge join query
  
  create table foo ( a int, b int);
  
  insert into foo values(0,0);
  insert into foo values(1,1);
  insert into foo values(2,2);
  
  select /*+ USE_MERGE */ y.b 
  from foo x, foo y where x.a > 0 and x.a = y.a and x.b =y.a;
  
  select /*+ USE_MERGE */ y.b , z.b
  from foo x, foo y, foo z where x.a > 0 and x.a = y.a and x.b =y.a and x.a = z.a and x.b = z.b;
  
  drop foo;