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
Oracle Weblogic Server - Version: 10.3.2 and later ]
Information in this document applies to any platform.
- 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.
To view full details, sign in with your My Oracle Support account.
Don't have a My Oracle Support account? Click to get started!