Kodo 4.2 - JDO - Not Handling Bi-Direcitonal Relationships Efficiently. (Doc ID 1089968.1)

Last updated on MAY 24, 2017

Applies to:

Oracle Kodo - Version: 4.1 and later   [Release: and later ]
Oracle Weblogic Server - Version: 10.3.2 and later ]
Information in this document applies to any platform.

Symptoms

Given the following scenario using Kodo 4.2 JDO:
- Parent object has a one-to-many relationship to Child objects.
- Child has a field that is a reference back to the Parent (so a bi-directional relationship).
- The Child mapping of the field that references back to the Parent uses the default-fetch-group attribute

When setting a fetch plan programmatically that includes retrieving fields on Parent object (including the field that contains a collection of Child objects) plus Child's field that is a reference back to Parent, it was found that the SQL generated was very inefficient.  First a query looks up the fields for the Parent.  Next, there is a query for each Child element to look up its parent, even though the parents were looked up in the first query.

Changes

None.

Cause

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