简单的jsf spring hibernate应用程序非常慢

Question

我正在学习Hibernate并使用Eclipse Helios作为IDE，Oracle11g作为数据库和Glassfish 3作为服务器来玩它。我正在关注一个简​​单的申请 (JSF+Spring+Hibernate)

我发现一个简单的选择和插入很慢，几乎需要25秒才能进行选择查询。我想知道为什么与普通的JDBC相比它会变慢。

以下是来自server.log，当我刷新我的页面时，同一个查询正在执行五次。这是缓慢的原因吗？

INFO: Hibernate: select customer0_.CUSTOMER_ID as CUSTOMER1_0_, 
customer0_.NAME as NAME0_, customer0_.ADDRESS as ADDRESS0_, customer0_.
CREATED_DATE as CREATED4_0_ from scott.customer customer0_

INFO: Hibernate: select customer0_.CUSTOMER_ID as CUSTOMER1_0_, 
customer0_.NAME as NAME0_, customer0_.ADDRESS as ADDRESS0_, customer0_.
CREATED_DATE as CREATED4_0_ from scott.customer customer0_

INFO: Hibernate: select customer0_.CUSTOMER_ID as CUSTOMER1_0_, 
customer0_.NAME as NAME0_, customer0_.ADDRESS as ADDRESS0_, customer0_.
CREATED_DATE as CREATED4_0_ from scott.customer customer0_


INFO: Hibernate: select customer0_.CUSTOMER_ID as CUSTOMER1_0_, 
customer0_.NAME as NAME0_, customer0_.ADDRESS as ADDRESS0_, customer0_.
CREATED_DATE as CREATED4_0_ from scott.customer customer0_


INFO: Hibernate: select customer0_.CUSTOMER_ID as CUSTOMER1_0_, customer0_.
NAME as NAME0_, customer0_.ADDRESS as ADDRESS0_, customer0_.
CREATED_DATE as CREATED4_0_ from scott.customer customer0_

任何见解或帮助都非常值得赞赏。

Answer 1

好吧，我认为执行相同的查询5次不太可能是加载页面的最有效方式。

理解Hibernate等工具在幕后做什么很重要，也就是说你不能假设一切都会发挥作用。因此，查看生成的SQL肯定是正确的做法。

但是，您只能通过分析应用程序来回答您的问题。如果您发现查询需要25秒才能执行，那么您应该查看Oracle诊断工具。