[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-3414) fetch profiles

[Steve Ebersole (JIRA)]

    [ http://opensource.atlassian.com/projects/hibernate/browse/HHH-3414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=33531#action_33531 ] 

Steve Ebersole commented on HHH-3414:
-------------------------------------

My issue with allowing "extension" of fetch profiles is what Hibernate terms "second passes".  Basically, every time we encounter an extends we have to account for the possibility that the thing extended is not yet defined (forward references).  It adds complexity and overhead to the process.  And is it really worth it?  

> fetch profiles
> --------------
>
>                 Key: HHH-3414
>                 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-3414
>             Project: Hibernate Core
>          Issue Type: New Feature
>          Components: core, metamodel
>            Reporter: Steve Ebersole
>            Assignee: Steve Ebersole
>             Fix For: 3.5
>
>
> The concept of fetch profiles as we are discussing here is basically to allow users to dynamically affect the mapped fetching strategy for associations at runtime.
> Consider the following example:
> <class name="Person">
>     ...
>     <set name="addresses" lazy="true" fetch="subselect" ...>
>         ...
>     </set>
> </class>
> <class name="Address">
>     ...
> </class>
> This follows the normal recommendation to map associations as lazy and use a dynamic fetching strategy (ala HQL/Criteria) to modify this lazy behavior at runtime.
> The fetaure discussed here would allow the same behavior for loading as well:
> <hibernate-mapping>
>     <fetch-profile name="person-details">
>         <fetch path="Person.addresses" style="join"/>
>     </fetch-profile>
> </hibernate-mapping>
> Or:
> <hibernate-mapping>
> <class name="Person">
>     ...
>     <fetch-profile name="person-details">
>         <fetch path="addresses" style="join"/>
>     </fetch-profile>
>     <set name="addresses" lazy="true" fetch="subselect" ...>
>         ...
>     </set>
> </class>
> </hibernate-mapping>
> Now, doing:
> session.enableFetchProfile( "person-details" ).get( Person.class, 1 )...
> will load Person#1 as well as their addresses in a single joined query.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira