RegisterObject(Object) vs. registerNewObject(Object)

Question

Hi all,
I need to decide the approach for my new application when creating new objects using Unit of Work. What do you recommend for registering the object? I have to confess that I’m a little confused. Each article or topic that I read makes me think differently from the previous one.
Should I use the registerObject(Object) call or the alternate method registerNewObject(Object)?
What I am planning to do is to use registerNewObject(Object), but checking if the object is already in cache.
I read that registerNewObject(Object) allows the user to perform primary key queries and has performance improvements since it does not clone the object.
Is this approach correct? What do you recommend for this case?
Here is a sample code of what I’m planning to do:
public Object insertObject(Object anObject, UnitOfWork uow) throws XxxException, TopLinkException
//Check if object is already in cache
Vector key = uow.keyFromObject(anObject);
Object obj = uow.getFromIdentityMap(key, anObject.getClass());
if (obj != null)
throw new XxxException("", key.toString());
return uow.registerNewObject(anObject);
Thanks in advance,
Ana Paula Carvalho

Answer 1

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Q1) please also tel me can collection whould be better if use nested table or assocative arrya or varry,
insted of object and record to make table. i personly found object and record easy to understand. please suggest ,as i will use them in many functions.
and in which situation, which one whould be better, with respect to performance and mantainabiliity.
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Use a nested table. You don't need an associative array.
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and please consider i want to use it like table ex IN "JOIN", in subquery , on right side of IN, EXISTS etc.
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A pipelined function is your only choice if you want to query it like a table. Use object types
-- type to match emp record
create or replace type emp_scalar_type as object
  (EMPNO NUMBER(4) ,
   ENAME VARCHAR2(10),
   JOB VARCHAR2(9),
   MGR NUMBER(4),
   HIREDATE DATE,
   SAL NUMBER(7, 2),
   COMM NUMBER(7, 2),
   DEPTNO NUMBER(2)
-- table of emp records
create or replace type emp_table_type as table of emp_scalar_type
-- pipelined function
create or replace function get_emp( p_deptno in number )
  return emp_table_type
  PIPELINED
  as
   TYPE EmpCurTyp IS REF CURSOR RETURN emp%ROWTYPE;
    emp_cv EmpCurTyp;
    l_rec  emp%rowtype;
  begin
    open emp_cv for select * from emp where deptno = p_deptno;
    loop
      fetch emp_cv into l_rec;
      exit when (emp_cv%notfound);
      pipe row( emp_scalar_type( l_rec.empno, LOWER(l_rec.ename),
          l_rec.job, l_rec.mgr, l_rec.hiredate, l_rec.sal, l_rec.comm, l_rec.deptno ) );
    end loop;
    return;
  end;
select * from table(get_emp(20))