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From Craig Russell <Craig.Russ...@Sun.COM>
Subject Re: Support java.lang.Object as FCO
Date Thu, 18 Aug 2005 02:56:59 GMT
Hi Michelle,

On Aug 17, 2005, at 3:14 PM, Michelle Caisse wrote:

> Hi Craig,
>
> I think the spec could be more explicit.

I agree. I'm trying to make it so.

> Embedded and serialized are syntactically orthogonal but not  
> semantically orthogonal;  therefore, they should be discussed  
> together somewhere.

Good idea.

> The spec should state that embedded="true" and serialized="true"  
> are mutually exclusive.

I agree.

> Also a discussion of the meaning of embedded="false"  
> serialized="false" for PC instances would be useful.

This discussion needs to include embedded-value, embedded-key, and  
embedded-element. And I agree. This is an issue that I added to the  
"to be resolved before FCS" of the JDO spec.

> Maybe this belongs in Chapter 15.

I've been thinking of Chapter 15 as non-normative. All the required  
behavior should be in chapter 18. What do you think?

Craig
>
> -- Michelle
>
> Craig Russell wrote:
>
>
>> Hi Andy,
>>
>> On Aug 17, 2005, at 10:39 AM, Andy Jefferson wrote:
>>
>>
>>> Hi Michelle,
>>>
>>>
>>>
>>>> It seems that jpox maps Object as serialized by default.  Where   
>>>> there is
>>>> no serialized or embedded attribute on the field, we map to a  
>>>> FK  column,
>>>> e.g. OBJECT102 BIGINT REFERENCES SIMPLE_CLASS, giving a jpox error:
>>>>
>>>>
>>>
>>> Well we interpret all types as serialized="false", but in  
>>> section  18.14 of the
>>> spec "java.lang" types (which Object is) are to be  
>>> embedded="true" by
>>> default. So we interpret this as serialising the Object into the   
>>> table of the
>>> class, into a BLOB column.
>>>
>>
>>
>> I tried to be more explicit about this in the Proposed Final  
>> Draft,  to say that embedded="true" doesn't mean serialized but  
>> embedded  column by column. Just like embedded PC instances.
>>
>> Could you please take a look at the PFD and see if this is not  
>> clear  enough?
>>
>> Thanks,
>>
>> Craig
>>
>>
>>>
>>>
>>>
>>>> SimpleInterface, which we map identically to Object, works fine.
>>>>
>>>>
>>>
>>> Because we treat an Interface as embedded="false" by default  
>>> (since  it's not
>>> specified in the list of embedded types in 18.14, so its  
>>> effectively a
>>> PersistenceCapable in that respect).
>>>
>>>
>>> -- 
>>> Andy
>>>
>>>
>>
>> Craig Russell
>> Architect, Sun Java Enterprise System http://java.sun.com/products/ 
>> jdo
>> 408 276-5638 mailto:Craig.Russell@sun.com
>> P.S. A good JDO? O, Gasp!
>>
>>
>>
>
>

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!


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