Reusing Static Data ADF Server Performance

9-4 Oracle Fusion Middleware Performance and Tuning Guide Fetch Size The JDBC fetch size gives the JDBC driver a hint as to the number of rows that should be fetched from the database when more rows are needed. For large queries that return a large number of objects, you can configure the row fetch size used in the query to improve performance by reducing the number database hits required to satisfy the selection criteria. See Also: Using EclipseLink JPA Extensions - Fetch Size at http:wiki.eclipse.orgUsing_ EclipseLink_JPA_Extensions_ELUGBind_ Parameters Most JDBC drivers use a default fetch size of 10. If you are reading 1000 objects, increasing the fetch size to 256 can significantly reduce the time required to fetch the querys results. Note: The default value means use the JDBC driver default value, which is typically 10 rows for the Oracle JDBC driver. To configure this, use query hint eclipselink.jdbc.fetch-size. Default Value: 0 The optimal fetch size is not always obvious. Usually, a fetch size of one half or one quarter of the total expected result size is optimal. Note that if you are unsure of the result set size, incorrectly setting a fetch size too large or too small can decrease performance. Batch Writing Batch writing can improve database performance by sending groups of INSERT, UPDATE, and DELETE statements to the database in a single transaction, rather than individually. The persistence property in persistence.xml eclipselink.jdbc.batch-writing=JDBC is used to configure this. See Also: How to Use Batch Writing for Optimization at http:wiki.eclipse.orgOptimizing_the_ EclipseLink_Application_ELUGHow_to_ Use_Batch_Writing_for_Optimizatio Default Value: Off Enable for the persistence unit. Change Tracking This is an optimization feature that lets you tune the way EclipseLink detects changes in an Entity. See Also: Using EclipseLink JPA Extensions for Tracking Changes at http:wiki.eclipse.orgUsing_ EclipseLink_JPA_Extensions_ ELUGUsing_EclipseLink_JPA_ Extensions_for_Tracking_Changes Default Value: AttributeLevel if using weaving Java EE default, otherwise Deferred. Leave at default AttributeLevel for best performance. Weaving Can disable through persistence.xml properties eclipselink.weaving Default Value: On Leave on for best performance. Table 9–1 Cont. EJBJPA Using Efficient SQL Statements and Querying Tuning Parameter Description Performance Notes