No1UNo wrote:
>
>
> Pinaki Poddar wrote:
>>
>> try:
>> javax.persistence.Query q = em.createQuery(aJPQLString);
>> q.setHint("openjpa.Subclasses", "false");
>>
>
> This promises to be exactly the solution I need to an optimization
> issue...but it does not work for me in OpenJPA 1.2.1. The 1.2.x
> documentation does not mention this parameter anywhere I could find, but
> the 'org.apache.openjpa.persistence.HintHandler' class in OpenJPA 2.0
> does. I assumed this must be a 2.0 feature.
>
> So I fell back to trying openjpa.jdbc.SubclassFetchMode, but the child
> classes were returned. I tried annotating with
> '@SubclassFetchMode(value=FetchMode.NONE)', but again the child classes
> were returned. I then searched through the 1.2.1 source code and found,
> to my surprise, at
> 'openjpa-persistence/src/main/java/org/apache/openjpa/persistence/QueryImpl.java'
> in the 'setHint' function that this is indeed supported in 1.2.1. But
> again, the child classes are returned.
>
> Does the setHint call need to be performed in combination with something
> else?
>
Given classes Y and Z descended from X via joined inheritance, I am
attempting to do the following:
Query dbQuery = em.createNativeQuery("SELECT * FROM xTable WHERE ...",
X.class);
dbQuery.setHint("openjpa.Subclasses", "false");
List<X> results = dbQuery.getResultList();
The intent is to quickly scan through the table for appropriate matches.
This might then return a large list. Then followups look at specific
subsets. I am hoping to disable subclass resolution in the initial search
but retain it for all subsequent ones.
Following in the debugger, I can see that the setHint function does
establish a new extent within the query for which subclasses is false. I do
not, however, see this information being used in the query execution.
Any guidance or even crazy suggestions would be welcome.
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