[ https://issues.apache.org/jira/browse/OPENJPA-1163?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Ravi P Palacherla updated OPENJPA-1163:
---------------------------------------
Attachment: OPENJPA-1163_trunk.patch
Attached is a test case and fix for the issue.
> Data consistency issues while modifying collections.
> ----------------------------------------------------
>
> Key: OPENJPA-1163
> URL: https://issues.apache.org/jira/browse/OPENJPA-1163
> Project: OpenJPA
> Issue Type: Bug
> Affects Versions: 2.0.0
> Environment: openJPA trunk. Derby DB.
> Reporter: Ravi P Palacherla
> Assignee: Ravi P Palacherla
> Attachments: OPENJPA-1163_trunk.patch
>
>
> There are data consistency issues when modifying more number of elements in a collection Vs less number of elements.
> Following is a detailed explanation about the issue with example:
>
> - Entity A has a collection of Entities AItems with cascade ALL.
> - Test case :
> Clear all the data inside tables representing Entity A and AItems.
> Create 3 entity managers em1,em2 and em3.
>
> em1.begin()
> create A on em1 with id "1"
> add 10 elements of AItems (id's from 0-9) to the created A(id 1).
> persist A.
> em1.commit()
>
> em1.begin()
> merge A ( created in the previous step)
> Remove 3 elements of AItems from the merged A.
> Add 3 elements of AItems ( id's 10,11,12) to the merged A (id 1).
>
> With out committing em1
>
> em2.begin()
> query database to fetch A and construct object result2 of entity A.
> Add 3 elements of AItems ( id's 13,14,15) to fetched A ( result2)
> em2.commit ()
> em1.commit()
>
> em3.begin()
> query database to check the size of AItems that are related to A ( id 1)
> em3.commit()
>
> The result on em3's query for AItems related to A, returns 13 as expected.
> 13 ( Initial 10 - em1's 3 + em1's 3 + em2's 3).
>
> When the same test case is repeated with removing and adding 10 elements instead of 3 as before then I get wrong results.
>
> Add initial 10 AItems (id's 0-9) for A.
> commit()
>
> em1 will remove 10 AItems from the collection of A.
> em1 will add 10 AItems (id's 10-19) to collection of A.
>
> em2 will add 10 AItems (id's 20-29) to collection of A.
>
> Commit em2.
> Commit em1.
>
> Then instead of 20 elements ( Initial 10 - em1's 10 + em1's 10 + em2's 10), I see only 10 elements.
>
> The 10 elements that I see are from em1's added AItems ( id's 10-19).
> I think the cause of the issue is that, when more number of elements (compared to initial element count of collection) in a collection are modified then collection tracking is disabled and openJPA tries to do the following:
> -- Delete every thing from the collection
> -- Insert data back to collection.
> While Inserting the data back it does not consider adding the dirty records ( em2's 10 added elements ) because the collection tracking is disabled.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.