15. 性能

下面我们展示 [JUnitTestPushTheLimits] 测试（2,500 个类别，5,000 种产品）在 24 种可能配置（6 种 DBMS * (1 种 JDBC + 3 种 JPA)）下的执行时间。这些数字的绝对值本身并无实际意义，其价值仅在于相互比较。 我们不做任何结论，留待读者自行判断。请注意，由于我们运行的是适用于所有 24 种配置的通用测试，因此并未利用 JPA 实现的特定功能。这可能会改变下文的结果。

针对每种DBMS，我们先删除了[dbproduitscategories]数据库，随后重建该数据库以进行四项连续测试。

MySQL 5 社区版

实现	执行配置	持续时间（秒）
JDBC	spring-jdbc-generic-04-JUnitTestPushTheLimits	47.555
JPA Hibernate	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	94,919
JPA EclipseLink	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	91,571
JPA OpenJPA	spring-jpa-generic-JUnitTestPushTheLimits-openjpa	100,387

Oracle Express 11g Release 2

实施	运行配置	耗时（秒）
JDBC	spring-jdbc-generic-04-JUnitTestPushTheLimits	108.590
JPA Hibernate	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	154,883
JPA EclipseLink	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	143,010
JPA OpenJPA	spring-jpa-generic- JUnitTestPushTheLimits-openjpa	90,874

PostgreSQL 9.4

实现	运行配置	耗时（秒）
JDBC	spring-jdbc-generic-04-JUnitTestPushTheLimits	86.074
JPA Hibernate	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	203,358
JPA EclipseLink	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	183,995
JPA OpenJpa	spring-jpa-generic-JUnitTestPushTheLimits-openjpa	197,068

IBM DB2 Express-C 10.5

实施	运行配置	耗时（秒）
JDBC	spring-jdbc-generic-04-JUnitTestPushTheLimits	285,000
JPA Hibernate	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	332,247
JPA EclipseLink	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	371,619
JPA OpenJPA	spring-jpa-generic-JUnitTestPushTheLimits-openjpa	253,953

SQL Server 2014 精简版

实现	运行配置	耗时（秒）
JDBC	spring-jdbc-generic-04-JUnitTestPushTheLimits	81.437
JPA Hibernate	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	216,15
JPA EclipseLink	spring-jpa-generic-JUnitTestPushTheLimits- hibernate-eclipselink	214.398
JPA OpenJPA	spring-jpa-generic-JUnitTestPushTheLimits-openjpa	236,691

Firebird 2.5.4

实现	运行配置	耗时（秒）
JDBC	spring-jdbc-generic-04-JUnitTestPushTheLimits	132.305
JPA Hibernate	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	304,458
JPA EclipseLink	spring-jpa-generic-JUnitTestPushTheLimits-hibernate-eclipselink	257,555
JPA OpenJPA	spring-jpa-generic-JUnitTestPushTheLimits-openjpa	363,546