May I know what does this question asking?

Hi, I don't understand what does this question asking:

Under which two conditions can the developer expect the persistence provider to ensure that all changes made to the persistence context in the transaction are visible to the processing of the query?

I just don't understand the term "visible to the processing of the query".

Can anyone please explain to me?

Thank You very much

I think this question goes about the situation where you first perform operations on the entitymanger and then you use run a query (JPQL) that uses this data also in one transaction.

To rephrase: If you for example update an entity using the entitymanager and then you run a query that will display fields from that entity, how can you make sure the query reflects the changes you've done via the entity manager?

--> See the FlushModeType :
http://download.oracle.com/javaee/5/api/javax/persistence/FlushModeType.html