如何使用休眠和弹簧启动启用批处理插入

java hibernate spring jpa spring-boot

2022-09-01 09:04:34

我想将大量实体插入到交叉表中。为此，我想启用休眠的批处理插入选项，以便每个插入一次添加不是1行，而是20或50行。

我正在尝试重现休眠教程中的结果。我创建了一个测试函数，该函数将尝试插入30个客户，就像示例中所示：

//Batch inserting test entities
//This code is inside transaction already, so I'm not creating a new one
entityManager.flush();
for (int i = 0; i < 30; ++i) {
    Customer customer = new Customer("Customer" + i, (i + 5) * 1000, "Position " + i);
    entityManager.persist(customer);
    if (i % 20 == 0) {
        entityManager.flush();
        entityManager.clear();
    }
}
entityManager.flush();
entityManager.clear();

客户类没有生成的 ID。

@Entity
public class Customer {

    @Id
    private String id;
    @Column
    private String name;
    @Column
    private long salary;
    @Column
    private String position;

    public Customer() {

    }

    public Customer(String name, long salary, String position) {
        this.id = UUID.randomUUID().toString();
        this.name = name;
        this.salary = salary;
        this.position = position;
    }

}

我期望看到的是 2 个插入语句，一个用于 20 条记录，一个用于 10 条记录。但是，当我打开postgres日志时，我看到30个插入语句，每个语句仅插入1行。我已经仔细检查了是否可以使用postgres插入多行。

我相信问题是由参数引起的，我应该将其传递到休眠状态。但是，由于我使用的是spring boot，因此我唯一的配置文件是appplication.properties。所以我尝试将其插入那里：hibernate.jdbc.batch_size 20

hibernate.jdbc.batch_size=20
hibernate.order_inserts=true
hibernate.order_updates=true
hibernate.jdbc.batch_versioned_data=true
spring.jpa.hibernate.jdbc.batch_size=20
spring.jpa.hibernate.order_inserts=true
spring.jpa.hibernate.order_updates=true
spring.jpa.hibernate.jdbc.batch_versioned_data=true
spring.jpa.properties.hibernate.jdbc.batch_size=20
spring.jpa.properties.hibernate.order_inserts=true
spring.jpa.properties.hibernate.order_updates=true
spring.jpa.properties.hibernate.jdbc.batch_versioned_data=true

根据这个答案，这应该足够了，但我也尝试将这些参数复制到我的jar中的文件中，并通过命令行提供参数：如本文档所述。hibernate.properties-Dhibernate.jdbc.batch_size=20

这些都无济于事。
我也找不到在我的代码中读取批大小属性的方法。似乎hibernate文档中提到的大多数对象在spring boot应用程序中都不存在。
如何在弹簧启动应用程序中启用休眠的批量插入？

我创建了一个最小的工作示例来重现问题：https://github.com/Alexey-/spring-boot-batch

在收到Vlad Mihalcea的答案后，我意识到是的，实际上批处理语句正在起作用，至少在休眠和jdbc级别上是这样。

但是，postgres日志本身表现出非常有趣的行为：对于批处理插入和普通插入的情况，它们几乎相同。

我最初期望看到的是，休眠将使用这样的语句：

test=# INSERT INTO customer (name, position, salary, id) values ('CustomerX', 'PositionX', '1000', 'idX'), ('CUSTOMERY', 'POSITIONY', '1000', 'idY');

这将产生类似于以下内容的日志记录：

2015-12-15 11:43:33.238 MSK LOG:  statement: INSERT INTO customer (name, position, salary, id) values ('CustomerX', 'PositionX', '1000', 'idX'), ('CUSTOMERY', 'POSITIONY', '1000', 'idY');

但是，事实并非如此。
当启用批量插入时（p6spy显示语句实际上是批处理的），postgres将生成类似于以下内容的日志：

2015-12-15 12:07:00.638 MSK LOG:  execute <unnamed>: BEGIN
2015-12-15 12:07:00.638 MSK LOG:  duration: 0.000 ms
2015-12-15 12:07:00.638 MSK LOG:  duration: 0.000 ms  parse <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.638 MSK LOG:  duration: 0.000 ms  bind <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.638 MSK DETAIL:  parameters: $1 = 'Customer0', $2 = 'Position 0', $3 = '0', $4 = '9c6a86fb-c991-4e98-aa65-fa736ef67dd7'
2015-12-15 12:07:00.638 MSK LOG:  execute <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.638 MSK DETAIL:  parameters: $1 = 'Customer0', $2 = 'Position 0', $3 = '0', $4 = '9c6a86fb-c991-4e98-aa65-fa736ef67dd7'
2015-12-15 12:07:00.639 MSK LOG:  duration: 1.000 ms
2015-12-15 12:07:00.648 MSK LOG:  duration: 0.000 ms  parse S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.648 MSK LOG:  duration: 0.000 ms  bind S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.648 MSK DETAIL:  parameters: $1 = 'Customer1', $2 = 'Position 1', $3 = '10', $4 = 'c8b2669c-044a-4a4d-acbd-31c3bcd9a783'
2015-12-15 12:07:00.648 MSK LOG:  execute S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.648 MSK DETAIL:  parameters: $1 = 'Customer1', $2 = 'Position 1', $3 = '10', $4 = 'c8b2669c-044a-4a4d-acbd-31c3bcd9a783'
2015-12-15 12:07:00.648 MSK LOG:  duration: 0.000 ms
2015-12-15 12:07:00.648 MSK LOG:  duration: 0.000 ms  bind S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.648 MSK DETAIL:  parameters: $1 = 'Customer2', $2 = 'Position 2', $3 = '20', $4 = '1c694f41-2ce7-4ee2-a0c0-f359690506f0'
2015-12-15 12:07:00.649 MSK LOG:  execute S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.649 MSK DETAIL:  parameters: $1 = 'Customer2', $2 = 'Position 2', $3 = '20', $4 = '1c694f41-2ce7-4ee2-a0c0-f359690506f0'
2015-12-15 12:07:00.649 MSK LOG:  duration: 0.000 ms
2015-12-15 12:07:00.649 MSK LOG:  duration: 0.000 ms  bind S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.649 MSK DETAIL:  parameters: $1 = 'Customer3', $2 = 'Position 3', $3 = '30', $4 = '1815947d-2604-48d4-a6be-43f6905130cf'
2015-12-15 12:07:00.649 MSK LOG:  execute S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.649 MSK DETAIL:  parameters: $1 = 'Customer3', $2 = 'Position 3', $3 = '30', $4 = '1815947d-2604-48d4-a6be-43f6905130cf'
2015-12-15 12:07:00.649 MSK LOG:  duration: 0.000 ms
2015-12-15 12:07:00.649 MSK LOG:  duration: 0.000 ms  bind S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.649 MSK DETAIL:  parameters: $1 = 'Customer4', $2 = 'Position 4', $3 = '40', $4 = 'cc521007-820f-4d58-8e1a-16a166aa91cf'
2015-12-15 12:07:00.649 MSK LOG:  execute S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:07:00.649 MSK DETAIL:  parameters: $1 = 'Customer4', $2 = 'Position 4', $3 = '40', $4 = 'cc521007-820f-4d58-8e1a-16a166aa91cf'
2015-12-15 12:07:00.649 MSK LOG:  duration: 0.000 ms
... the rest of the logs is identical and do not provide any valuable information...

当批处理语句被禁用时（p6spy显示不执行批处理），日志将如下所示：

2015-12-15 12:09:00.246 MSK LOG:  execute <unnamed>: BEGIN
2015-12-15 12:09:00.246 MSK LOG:  duration: 0.000 ms
2015-12-15 12:09:00.246 MSK LOG:  duration: 0.000 ms  parse <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.246 MSK LOG:  duration: 0.000 ms  bind <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.246 MSK DETAIL:  parameters: $1 = 'Customer0', $2 = 'Position 0', $3 = '0', $4 = '9e085ad0-437f-4d7d-afaa-e342e031cbee'
2015-12-15 12:09:00.246 MSK LOG:  execute <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.246 MSK DETAIL:  parameters: $1 = 'Customer0', $2 = 'Position 0', $3 = '0', $4 = '9e085ad0-437f-4d7d-afaa-e342e031cbee'
2015-12-15 12:09:00.246 MSK LOG:  duration: 0.000 ms
2015-12-15 12:09:00.248 MSK LOG:  duration: 0.000 ms  parse <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.248 MSK LOG:  duration: 0.000 ms  bind <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.248 MSK DETAIL:  parameters: $1 = 'Customer1', $2 = 'Position 1', $3 = '10', $4 = 'f29cfa40-7d24-49a6-ae5d-2a2021932d80'
2015-12-15 12:09:00.248 MSK LOG:  execute <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.248 MSK DETAIL:  parameters: $1 = 'Customer1', $2 = 'Position 1', $3 = '10', $4 = 'f29cfa40-7d24-49a6-ae5d-2a2021932d80'
2015-12-15 12:09:00.249 MSK LOG:  duration: 1.000 ms
2015-12-15 12:09:00.250 MSK LOG:  duration: 0.000 ms  parse <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.250 MSK LOG:  duration: 0.000 ms  bind <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.250 MSK DETAIL:  parameters: $1 = 'Customer2', $2 = 'Position 2', $3 = '20', $4 = '067dd6d4-5060-467f-b533-75994ecbaedc'
2015-12-15 12:09:00.250 MSK LOG:  execute <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.250 MSK DETAIL:  parameters: $1 = 'Customer2', $2 = 'Position 2', $3 = '20', $4 = '067dd6d4-5060-467f-b533-75994ecbaedc'
2015-12-15 12:09:00.250 MSK LOG:  duration: 0.000 ms
2015-12-15 12:09:00.250 MSK LOG:  duration: 0.000 ms  parse <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.250 MSK LOG:  duration: 0.000 ms  bind <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.251 MSK DETAIL:  parameters: $1 = 'Customer3', $2 = 'Position 3', $3 = '30', $4 = '7df32327-f2f5-4011-848d-55aafb3f09fa'
2015-12-15 12:09:00.251 MSK LOG:  execute <unnamed>: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.251 MSK DETAIL:  parameters: $1 = 'Customer3', $2 = 'Position 3', $3 = '30', $4 = '7df32327-f2f5-4011-848d-55aafb3f09fa'
2015-12-15 12:09:00.251 MSK LOG:  duration: 0.000 ms
2015-12-15 12:09:00.251 MSK LOG:  duration: 0.000 ms  parse S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.251 MSK LOG:  duration: 0.000 ms  bind S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.251 MSK DETAIL:  parameters: $1 = 'Customer4', $2 = 'Position 4', $3 = '40', $4 = '1e55ab6a-8780-4c8f-8af2-2886d954f819'
2015-12-15 12:09:00.251 MSK LOG:  execute S_1: insert into customer (name, position, salary, id) values ($1, $2, $3, $4)
2015-12-15 12:09:00.251 MSK DETAIL:  parameters: $1 = 'Customer4', $2 = 'Position 4', $3 = '40', $4 = '1e55ab6a-8780-4c8f-8af2-2886d954f819'
2015-12-15 12:09:00.251 MSK LOG:  duration: 0.000 ms
... the rest of the logs is identical and do not provide any valuable information...

因此，两者之间的唯一区别是当禁用批处理时，postgres将花费更多的时间来意识到它应该重用预准备的语句。

因此，我决定运行性能测试来确认这一点。
我尝试将30.000条记录插入空数据库。
禁用批处理后，需要 334 毫秒。
启用批处理后，需要 4650 毫秒！

因此，我删除了对entityManager.flush的所有调用（只留下entityManager.clear），时间下降到320ms。我不知道为什么hibernate的教程建议使用齐平。我想这只是一个错误。

所以我想底线是这样的：批处理正在工作，但它并没有提供任何真正的好处（至少对于postgres）。此外，不正确地使用它（如教程中所示）可能会导致可怕的，可怕的结果。使用风险自负，并始终衡量实际性能提升。

答案 1

您的代码没有任何问题，并且工作正常。

我调试了它，然后我安装了p6spy，它正在工作。这也是您可以测试它的方法：

在添加此依赖项中：build.gradle
```
compile 'p6spy:p6spy:2.1.4'
```

修改连接属性，如下所示：

database.driver=com.p6spy.engine.spy.P6SpyDriver
database.url=jdbc:p6spy:postgresql://localhost:5432/

添加到文件夹中。您可以从此处下载。spy.propertiesresources

然后你会看到批处理语句：

2015-12-14 19:38:03.655  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114683655|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer0', 'Position 0', 5000, '9f92ac01-8156-41f1-9bdb-36ff622a99cc')
2015-12-14 19:38:03.658  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114683658|2|statement|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer0', 'Position 0', 5000, '9f92ac01-8156-41f1-9bdb-36ff622a99cc')
2015-12-14 19:38:04.212  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684212|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer1', 'Position 1', 6000, 'e3a1dc5a-2183-4fb0-aa9a-4fb8cace23a3')
2015-12-14 19:38:04.213  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684213|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer2', 'Position 2', 7000, '8824f5be-afe5-4a6a-ab8a-8f266db5973f')
2015-12-14 19:38:04.213  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684213|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer3', 'Position 3', 8000, '249304b3-19c5-4376-b5dc-2da685c1db64')
2015-12-14 19:38:04.213  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684213|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer4', 'Position 4', 9000, '2bf15945-94c3-45f8-b0d1-e2fedbdcbaca')
2015-12-14 19:38:04.214  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684214|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer5', 'Position 5', 10000, '85b2b999-5d84-4181-9c71-1a83b4d20b86')
2015-12-14 19:38:04.214  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684214|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer6', 'Position 6', 11000, '8ed6289e-3d04-4ba5-9285-9bce202c8dae')
2015-12-14 19:38:04.215  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684215|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer7', 'Position 7', 12000, '2fc489a8-c6c4-4984-808d-2da9a2e8ad4a')
2015-12-14 19:38:04.215  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684215|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer8', 'Position 8', 13000, '897cd341-b65b-4521-87e6-f4fb78b09bfd')
2015-12-14 19:38:04.215  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684215|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer9', 'Position 9', 14000, 'fa59d5a7-2570-43f9-ba46-595b8fcefa35')
2015-12-14 19:38:04.216  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684216|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer10', 'Position 10', 15000, '0b5b38d1-d644-4ea0-a3f0-9aa025463b8a')
2015-12-14 19:38:04.216  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684216|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer11', 'Position 11', 16000, 'afbb349f-cf28-4cfb-b5b8-73b4df6fa4b1')
2015-12-14 19:38:04.216  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684216|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer12', 'Position 12', 17000, 'd6719dc4-1dfd-433f-a8ae-4c931f461e78')
2015-12-14 19:38:04.216  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684216|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer13', 'Position 13', 18000, 'ca277f3c-d51e-493d-a4f7-a945879bd7d0')
2015-12-14 19:38:04.217  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684217|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer14', 'Position 14', 19000, '07014145-332b-4b4c-b320-9412443c45b6')
2015-12-14 19:38:04.217  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684217|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer15', 'Position 15', 20000, '8ffde083-420f-418d-b624-b059b9e28f3b')
2015-12-14 19:38:04.217  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684217|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer16', 'Position 16', 21000, '6ac39900-69db-408a-bda1-4d2706da49ba')
2015-12-14 19:38:04.217  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684217|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer17', 'Position 17', 22000, '45f6db1b-18cd-4986-8f46-ce8f02d9588d')
2015-12-14 19:38:04.217  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684217|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer18', 'Position 18', 23000, 'b4312298-a818-4b7a-9cff-7923328de4dc')
2015-12-14 19:38:04.218  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684218|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer19', 'Position 19', 24000, 'efe7e3d2-da11-40ce-9fee-6f77726499db')
2015-12-14 19:38:04.218  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684218|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer20', 'Position 20', 25000, 'd51484c3-36e2-4737-b5c9-135709ad1d30')
2015-12-14 19:38:04.808  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684808|2|statement|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer20', 'Position 20', 25000, 'd51484c3-36e2-4737-b5c9-135709ad1d30')
2015-12-14 19:38:04.811  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684811|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer21', 'Position 21', 26000, '8c7e0e43-f89f-4000-8367-3406974102f4')
2015-12-14 19:38:04.811  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684811|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer22', 'Position 22', 27000, 'ab757793-1c45-4861-aff8-aa5cea3c8bd5')
2015-12-14 19:38:04.812  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684812|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer23', 'Position 23', 28000, 'edf18735-cc27-437b-9a28-156f57b51343')
2015-12-14 19:38:04.812  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684812|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer24', 'Position 24', 29000, 'c882f053-2e9a-405f-bb94-3ba83303aefe')
2015-12-14 19:38:04.812  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684812|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer25', 'Position 25', 30000, 'd6af1feb-5842-4b40-816d-8e2aaa2ce9b3')
2015-12-14 19:38:04.812  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684812|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer26', 'Position 26', 31000, '48f6a4cb-5671-4b73-bb51-3e37964fa136')
2015-12-14 19:38:04.813  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684812|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer27', 'Position 27', 32000, '6ac59ed6-2a0f-4dbb-a6d7-7231a9c9d2cc')
2015-12-14 19:38:04.813  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684813|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer28', 'Position 28', 33000, '57565a6a-4e44-4fe0-86bd-837a9687487d')
2015-12-14 19:38:04.813  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684813|0|batch|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer29', 'Position 29', 34000, 'f3c2dbdd-5d54-4bf3-86d2-327c60ee5cc0')
2015-12-14 19:38:04.814  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684814|1|statement|connection 7|insert into customer (name, position, salary, id) values (?, ?, ?, ?)|insert into customer (name, position, salary, id) values ('Customer29', 'Position 29', 34000, 'f3c2dbdd-5d54-4bf3-86d2-327c60ee5cc0')
2015-12-14 19:38:04.817  INFO 14116 --- [io-18080-exec-3] p6spy  : 1450114684817|2|commit|connection 7||

第三列指示语句是在 JDBC 批处理中执行的。batch

前面一列表示执行语句所花费的毫秒数。带有的用于将语句添加到批处理时。batch0

第 3 列中包含的那些（因此在第 2 列中有 a 或 a）用于执行批处理的时间，对应于第 20 次和第 30 次迭代。statement12

答案 2