Hibernate对于大数据量处理之分表

    Hibernate如何处理大数据量的操作呢？主要是数据分库或分表存放，从而提高软件的运行及数据库访问的速度。下面介绍一下对于日志存储的数据分表操作。

    日志管理
----------------
1.导航栏-->日志管理
2.LogAction.findAllLogs();
 public String findAllLogs(){
  this.allLogs = logService.findAllEntities();
  return "logListPage" ;
 }
3.
4.

日志:
 数据量大:
 1.分表(动态表).
 2.分库.

logs
logs_2013_1
logs_2013_2

使用调度器动态生成日志表
------------------------------
0.dao和service增加执行原生sql语句的功能.
 dao
 -----------------
 public interface BaseDao<T> {
  ...
  public void executeSQL(String sql,Object...objects);
 }

 public class BaseDaImpl<T> ...{
  ...
  //执行原生的sql语句
  public void executeSQL(String sql,Object...objects){
   SQLQuery q = sf.getCurrentSession().createSQLQuery(sql);
   for(int i = 0 ; i < objects.length ; i ++){
    q.setParameter(i, objects[i]);
   }
   q.executeUpdate();
  }
 }

 service
 -----------------------
 public interface BaseService<T> {
  ...
  public void executeSQL(String sql,Object...objects);
 }

 public abstract class BaseServiceImpl<T> implements BaseService<T> {
  ...
  //执行原生的sql语句
  public void executeSQL(String sql,Object...objects){
   dao.executeSQL(sql, objects);
  }
 }
1.引入quartz类库
 com.springsource.org.quartz-1.6.2.jar
2.创建石英任务
 /**
  * 使用spring集成的石英调度,动态生成日志表
  */
 public class GenerateLogsTableTask extends QuartzJobBean {

  //
  private LogService logService ;
  
  public void setLogService(LogService logService) {
   this.logService = logService;
  }

  /**
   * 执行任务
   */
  protected void executeInternal(JobExecutionContext arg0) throws JobExecutionException {
   String tableName =  LogUtil.generateLogTableName(1);
   String sql = "create table if not exists " + tableName + " like logs";
   logService.executeSQL(sql);
   System.out.println(tableName + " 生成了! " );
   
   tableName =  LogUtil.generateLogTableName(2);
   sql = "create table if not exists " + tableName + " like logs";
   logService.executeSQL(sql);
   System.out.println(tableName + " 生成了! " );
  }
 }
3.配置调度任务
 [conf/schedules.xml]
 <?xml version="1.0"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:tx="http://www.springframework.org/schema/tx"
  xmlns:aop="http://www.springframework.org/schema/aop"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-3.0.xsd
       http://www.springframework.org/schema/tx
       http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop-3.0.xsd ">
  <!-- 任务明细bean,对石英任务包装 -->
  <bean id="jobDetailBean" class="org.springframework.scheduling.quartz.JobDetailBean">
   <property name="jobClass" value="cn.itcast.surveypark.schedule.GenerateLogsTableTask" />
   <property name="jobDataAsMap">
    <map>
     <entry key="logService" value-ref="logService" />
    </map>
   </property>
  </bean>
  
  <!-- cron触发器bean,设置任务的调度策略的 -->
  <bean id="cronTriggerBean" class="org.springframework.scheduling.quartz.CronTriggerBean">
   <property name="jobDetail" ref="jobDetailBean" />
   <!-- cron表达式 -->
   <property name="cronExpression">
    <value>0 0 0 15 * ?</value>
   </property>
  </bean>
  
  <!-- 调度器工厂bean,激活触发器,启动石英任务的 -->
  <bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
   <property name="triggers">
    <ref bean="cronTriggerBean"/>
   </property>
  </bean>
 </beans>
4.配置web.xml文件,一同加载spring的所有配置文件
 <!-- 通过上下文参数指定spring配置文件的位置 -->
 <context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:beans.xml,classpath:schedules.xml</param-value>
 </context-param>
5.修改时间,为触发任务接近的时间,比如2013-1-14 23:59:00秒
6.启动观察效果

使用spring监听器在服务器启动时完成当月日志表和下两个月日志表初始化
-------------------------------------------------------------------
 /**
  * 初始化日志表监听器
  */
 @SuppressWarnings("rawtypes")
 @Component
 public class IniLogTablesListener implements ApplicationListener{

  @Resource
  private LogService logService;
  
  public void onApplicationEvent(ApplicationEvent arg0) {
   //是否是上下文刷新事件
   if(arg0 instanceof ContextRefreshedEvent){
    String tableName = LogUtil.generateLogTableName(0);
    String sql = "create table if not exists " + tableName + " like logs";
    logService.executeSQL(sql);
    
    sql = "create table if not exists " + LogUtil.generateLogTableName(1) + " like logs";
    logService.executeSQL(sql);
    
    sql = "create table if not exists " + LogUtil.generateLogTableName(2) + " like logs";
    logService.executeSQL(sql);
    System.out.println("日志表-"+tableName+",初始化完成");
   }
  }
 }

可扩展性:scalable.伸缩性.

降低数据库存储压力:
 分表:整个库的数据量不是很大,但是某个(些)表的数据量较大.