MyBatis Plus大数据量查询慢原因分析及解决

@Configuration
public class MybatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

Page<User> page = new Page<>(1, 100); // 当前页, 每页条数
userMapper.selectPage(page, null);

@Select("SELECT * FROM large_table")
@Options(resultSetType = ResultSetType.FORWARD_ONLY, fetchSize = 1000)
@ResultType(User.class)
void selectLargeData(ResultHandler<User> handler);

try (Cursor<User> cursor = userMapper.selectCursor(null)) {
    cursor.forEach(user -> {
        // 单行处理逻辑
    });
}

@SqlParser(filter = true)
@Select("SELECT id, name FROM user WHERE status = 1")
List<User> selectActiveUsers();

List<User> userList = ... // 大数据集合
userService.saveBatch(userList, 1000); // 每批1000条

@DS("slave")
@Select("SELECT * FROM read_heavy_table")
List<Record> selectReadHeavyData();

-- 第一步：查询ID范围
SELECT id FROM large_table LIMIT 1000000, 1000;
-- 第二步：精确获取数据
SELECT * FROM large_table WHERE id IN (1,2,3...);

spring:
  datasource:
    hikari:
      maximum-pool-size: 20
      connection-timeout: 30000
      idle-timeout: 600000
      max-lifetime: 1800000

<dependency>
    <groupId>p6spy</groupId>
    <artifactId>p6spy</artifactId>
    <version>3.9.1</version>
</dependency>

appender=com.p6spy.engine.spy.appender.Slf4JLogger
logMessageFormat=com.p6spy.engine.spy.appender.CustomLineFormat
customLogMessageFormat=%(executionTime) ms | %(category) | %(sql)