In this scenario generally using the two transformations
(Joiner&UpdateStrategy Tx) if S1 and S2 are different 
sources or Flat files; 
  Else if both are in same sources as of relational then 
join it in SourceQulaifier Tx itself in this case no need 
for Joiner tx.

1) Joiner Tx will join the S1 and S2 by using common 
fields; here S2 is the Master table.

2)In UpdateStrategy Tx. Condition is like IIF
(s2.empno=s1.empno,1,0)