What

Group sql statements into a batch and submit them with one call to DB, rather than send each statement one by one, this is batch processing.

Why

Batch processing can reduce the amount of communication overhead, thereby improving  performance.

It is faster than sending them one by one without waiting for each one to finish, and the DB may be execute some of them in parallel.

How

In mybatis, we have two approaches to implement batch processing:

1. if integrate mybatis and spring

   <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
      <constructor-arg index="0" ref="sqlSessionFactory" />
   
      <constructor-arg index="1" value="BATCH" />
   
   </bean>
   

   then in code :

   for() {
   
      sqlSession.update();
   
   }
   

2. without spring

   SqlSession session = factory.openSession(ExecutorType.BATCH);			
   for(Child c : childs) {
   
     session.update("updateChild", c);
   
   }
   
   session.commit();