title: MERGE Statement is not working in Informix v10
body: <p>I tried to use the merge statement to Insert/Update in Informix v10.0
  but it throws a Syntax Error:</p>
  <pre><code>create table source(id int, account int, age int);
  create table target (id int, account int, age int);
  
  insert into source values(1, 1200, 25);
  insert into source values(2, 1300, 28);
  insert into source values(3, 1400, 45);
  
  merge into target t 
  using source s on t.id = s.id
  when matched then
  update
  set t.id = s.id, t.account = s.account, t.age = s.age
  when not matched then
  insert (t.id, t.account, t.age)
  values (s.id, s.account, s.age);
  
  select * from target;
  </code></pre>
  <p>Could you please help?</p>