Spring 数据 jpa 批量执行所有插入操作

Question

我需要在 mysql 中插入大量数据（大约 100k）然后我尝试使用 Spring 数据 Jpa 批量插入，为此我使用了一个包含 30 条记录的简单示例。

首先是删除@GeneratedValue os，我的实体端实现了Persistable，在插入之前不需要select：

@Entity
public class User implements Persistable {

    @Id
    private Integer id;
    // properties here...

然后，在我的 application.yml 上：

spring:
  jpa:
    properties:
      hibernate.jdbc.batch_size: 30
      hibernate.generate_statistics: true
    show-sql: true
    hibernate:
      ddl-auto: validate
  datasource:
    driverClassName: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/db?cachePrepStmts=true&reWriteBatchedInserts=true
    // user and password

我有一个简单的存储库：

public interface UserRepository extends JpaRepository<User, Integer> { }

和插入方法：

public void process() {

        List<User> users = new ArrayList<>();

        for (int i = 1 ; i <= 30; i++) {
            User user = new User();
            user.setId(i);
            // set properties

            users.add(user);

            if(i % 30 == 0) {
                userRepository.saveAll(users);
                users.clear();
            }
        }
    }

然后我认为正确的只是 1 批操作，但我有 29 条语句：

    1745893 nanoseconds spent acquiring 1 JDBC connections;
    0 nanoseconds spent releasing 0 JDBC connections;
    3524622 nanoseconds spent preparing 30 JDBC statements;
    68290171 nanoseconds spent executing 29 JDBC statements;
    215125391 nanoseconds spent executing 1 JDBC batches;
    0 nanoseconds spent performing 0 L2C puts;
    0 nanoseconds spent performing 0 L2C hits;
    0 nanoseconds spent performing 0 L2C misses;
    240389888 nanoseconds spent executing 1 flushes (flushing a total of 29 entities and 29 collections);
    0 nanoseconds spent executing 0 partial-flushes (flushing a total of 0 entities and 0 collections)

有什么想法吗？

谢谢！

Answer 1

测试下一个属性：

spring.jpa.properties.hibernate.order_inserts=true