-- 假设有一个名为my_table的表

-- 1. 查看表的当前HWM
SELECT segment_name, block_id, bytes FROM dba_extents WHERE segment_name = 'MY_TABLE';

-- 2. 释放未使用的空间
ALTER TABLE my_table DEALLOCATE UNUSED;

-- 3. 重新组织表，释放未使用的空间并压缩表
ALTER TABLE my_table MOVE;

-- 4. 再次查看表的HWM，确认是否已经降低
SELECT segment_name, block_id, bytes FROM dba_extents WHERE segment_name = 'MY_TABLE';

# 拉取Oracle官方Docker镜像
docker pull store/oracle/database-enterprise:12.2.0.1

# 运行Oracle容器
docker run -d -p 1521:1521 --name oracle-db store/oracle/database-enterprise:12.2.0.1

# 获取容器日志来查看数据库初始化信息
docker logs oracle-db

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class HelloWorldServlet extends HttpServlet {
    public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
            // 设置响应内容类型
            response.setContentType("text/html;charset=UTF-8");
            // 实际的逻辑是在这里
            PrintWriter out = response.getWriter();
            out.println("<h1>Hello World</h1>");
            out.println("这是您的第一个Tomcat应用程序!");
    }
}

pip install django

django-admin startproject myproject

cd myproject

python manage.py runserver

# 在源数据库上配置GoldenGate
# 添加 GoldenGate 用户并授权
sqlplus / as sysdba
CREATE USER ogg IDENTIFIED BY password;
GRANT connect, resource TO ogg;
GRANT alter session TO ogg;
GRANT create table TO ogg;
GRANT insert any table TO ogg;
GRANT delete any table TO ogg;
GRANT update any table TO ogg;
GRANT select any dictionary TO ogg;
GRANT alter any table TO ogg;

# 配置数据泵进程
mkdir -p /ogg
chown -R ogg:dba /ogg

# 初始化GoldenGate
$GoldenGate_dir/ggsci
GGSCI> create subdirs
GGSCI> add extract ext_source, tranlog, begin now
GGSCI> add rmttrail /ogg/dirdat/r, extract ext_source
GGSCI> add replicat rep_target, exttrail /ogg/dirdat/r, begin now

# 编辑 extract 参数文件
EXTRACT ext_source
USERID ogg, PASSWORD password
DISCARDFILE /ogg/dirrpt/ext_source.dsc, PURGE
DDL INCLUDE ALL
EXTTRAIL /ogg/dirdat/r
TABLE hr.*;

# 编辑 replicat 参数文件
REPLICAT rep_target
USERID ogg, PASSWORD password
ASSUMETARGETDEFS
DISCARDFILE /ogg/dirrpt/rep_target.dsc, PURGE
DDL ERRORMAX 50
MAP hr.*, TARGET hr.*;

GGSCI> start extract ext_source
GGSCI> start replicat rep_target

Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/mydb";
Connection conn = DriverManager.getConnection(url, "user", "password");

Class.forName("org.postgresql.Driver");
String url = "jdbc:postgresql://localhost:5432/mydb";
Connection conn = DriverManager.getConnection(url, "user", "password");

ALTER USER ommdba IDENTIFIED BY new_password;

ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED;

// 引入相关依赖

@SpringBootApplication
@EnableTransactionManagement
@MapperScan("com.yunwisdom.crm.mapper")
public class CrmApplication {
    public static void main(String[] args) {
        SpringApplication.run(CrmApplication.class, args);
    }
}

// 实体类示例
@Data
@TableName("crm_customer")
public class Customer {
    @TableId(type = IdType.AUTO)
    private Long id;
    private String name;
    private String email;
    // 其他字段...
}

// Mapper接口示例
@Mapper
public interface CustomerMapper extends BaseMapper<Customer> {
    // 这里可以添加自定义的数据库操作方法
}

// 服务层示例
@Service
public class CustomerService {
    @Autowired
    private CustomerMapper customerMapper;

    public List<Customer> getAllCustomers() {
        return customerMapper.selectList(null);
    }

    // 其他业务方法...
}

// 控制器示例
@RestController
@RequestMapping("/api/customers")
public class CustomerController {
    @Autowired
    private CustomerService customerService;

    @GetMapping
    public List<Customer> getAllCustomers() {
        return customerService.getAllCustomers();
    }

    // 其他API端点...
}

sudo apt update

sudo apt upgrade

sudo apt install <package_name>

apt search <package_name>

sudo apt remove <package_name>

sudo systemctl status

whoami

id

ls -l <file_or_directory>

sudo chmod <permissions> <file_or_directory>

ls

mkdir <new_directory>

rmdir <empty_directory>

rm <file_name>

cat <file_name>
nano <file_name>

date

ifconfig
ip addr

ps aux

sudo kill <process_id>

sudo apt install openssh-server

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <image>
                    <builder>paketobuildpacks/builder:tiny</builder>
                    <env>
                        <BP_NATIVE_IMAGE>true</BP_NATIVE_IMAGE>
                    </env>
                </image>
            </configuration>
        </plugin>
    </plugins>
</build>

./mvnw clean package -Pnative