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Difference between revisions of "EclipseLink/Examples/JPA/GraphLoading"
< EclipseLink | Examples | JPA
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A common problem developers face when using object-relational solutions is how to optimize the loading of a graph or related objects. By default a query for the root object type and default navigation through the graph can result in a N+1 SQL performance problem. This how-to highlights EclipseLink JPA's available solutions. | A common problem developers face when using object-relational solutions is how to optimize the loading of a graph or related objects. By default a query for the root object type and default navigation through the graph can result in a N+1 SQL performance problem. This how-to highlights EclipseLink JPA's available solutions. | ||
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+ | == Example Model == | ||
+ | |||
+ | == Querying without Optimizations == | ||
+ | |||
+ | == JPQL JOIN FETCH == | ||
+ | |||
+ | == EclipseLink Hints == | ||
+ | |||
+ | EclipseLink provides additional support for joining and batch reading using query hints. | ||
+ | |||
+ | === JOIN FETCH Hint === | ||
+ | |||
+ | === BATCH Hint === |
Revision as of 16:34, 3 April 2008
Contents
How to Optimize Object Graph Loading with JPA
A common problem developers face when using object-relational solutions is how to optimize the loading of a graph or related objects. By default a query for the root object type and default navigation through the graph can result in a N+1 SQL performance problem. This how-to highlights EclipseLink JPA's available solutions.
Example Model
Querying without Optimizations
JPQL JOIN FETCH
EclipseLink Hints
EclipseLink provides additional support for joining and batch reading using query hints.