Oracle 19C 数据库表被误删除的模拟恢复
Oracle 19C 数据库表被误删除的模拟恢复操作
1、模拟创建表用于恢复测试
sqlplus zzh/zzh
SQL> create table obj_tb tablespace users as select * from dba_objects;
Table created.
SQL> select count(*) from obj_tb;
COUNT(*)
----------
72373
2、记录当前状态下数据库的时间
SQL> select systimestamp from dual;
SYSTIMESTAMP
---------------------------------------------------------------------------
13-JUN-24 11.10.10.097481 AM +08:00
3、模拟表被误操作永久删除
SQL> drop table obj_tb purge;
Table dropped.
SQL> select * from obj_tb
2 ;
select * from obj_tb
*
ERROR at line 1:
ORA-00942: table or view does not exist
4、基于时间点通过RMAN恢复被删除的表
[oracle@oel backup]$ rman target /
Recovery Manager: Release 19.0.0.0.0 - Production on Thu Jun 13 11:11:57 2024
Version 19.3.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
connected to target database: ORCL (DBID=1699315892)
RMAN> recover table zzh.obj_tb until time "to_date('2024-06-13 11:10:10','yyyy-mm-dd hh24:mi:ss')" auxiliary destination '/u01/dump';
Starting recover at 2024-06-13 11:12:03
using target database control file instead of recovery catalog
current log archived
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=257 device type=DISK
RMAN-05026: warning: presuming following set of tablespaces applies to specified point-in-time
List of tablespaces expected to have UNDO segments
Tablespace SYSTEM
Tablespace UNDOTBS1
Creating automatic instance, with SID='pEpF'
initialization parameters used for automatic instance:
db_name=ORCL
db_unique_name=pEpF_pitr_ORCL
compatible=19.0.0
db_block_size=8192
db_files=200
diagnostic_dest=/u01/app/oracle
_system_trig_enabled=FALSE
sga_target=6144M
processes=200
db_create_file_dest=/u01/dump
log_archive_dest_1='location=/u01/dump'
#No auxiliary parameter file used
starting up automatic instance ORCL
Oracle instance started
Total System Global Area 6442448984 bytes
Fixed Size 8910936 bytes
Variable Size 1107296256 bytes
Database Buffers 5318377472 bytes
Redo Buffers 7864320 bytes
Automatic instance created
contents of Memory Script:
{
# set requested point in time
set until time "to_date('2024-06-13 11:10:10','yyyy-mm-dd hh24:mi:ss')";
# restore the controlfile
restore clone controlfile;
# mount the controlfile
sql clone 'alter database mount clone database';
# archive current online log
sql 'alter system archive log current';
}
executing Memory Script
executing command: SET until clause
Starting restore at 2024-06-13 11:12:23
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: SID=169 device type=DISK
channel ORA_AUX_DISK_1: starting datafile backup set restore
channel ORA_AUX_DISK_1: restoring control file
channel ORA_AUX_DISK_1: reading from backup piece /u01/backup/ctl_spf_c-1699315892-20240613-00.BKU
channel ORA_AUX_DISK_1: piece handle=/u01/backup/ctl_spf_c-1699315892-20240613-00.BKU tag=TAG20240613T110741
channel ORA_AUX_DISK_1: restored backup piece 1
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:01
output file name=/u01/dump/ORCL/controlfile/o1_mf_m6nrwr5f_.ctl
Finished restore at 2024-06-13 11:12:25
sql statement: alter database mount clone database
sql statement: alter system archive log current
contents of Memory Script:
{
# set requested point in time
set until time "to_date('2024-06-13 11:10:10','yyyy-mm-dd hh24:mi:ss')";
# set destinations for recovery set and auxiliary set datafiles
set newname for clone datafile 1 to new;
set newname for clone datafile 4 to new;
set newname for clone datafile 3 to new;
set newname for clone tempfile 1 to new;
# switch all tempfiles
switch clone tempfile all;
# restore the tablespaces in the recovery set and the auxiliary set
restore clone datafile 1, 4, 3;
switch clone datafile all;
}
executing Memory Script
executing command: SET until clause
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
executing command: SET NEWNAME
renamed tempfile 1 to /u01/dump/ORCL/datafile/o1_mf_temp_%u_.tmp in control file
Starting restore at 2024-06-13 11:12:29
using channel ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: starting datafile backup set restore
channel ORA_AUX_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_AUX_DISK_1: restoring datafile 00001 to /u01/dump/ORCL/datafile/o1_mf_system_%u_.dbf
channel ORA_AUX_DISK_1: restoring datafile 00004 to /u01/dump/ORCL/datafile/o1_mf_undotbs1_%u_.dbf
channel ORA_AUX_DISK_1: restoring datafile 00003 to /u01/dump/ORCL/datafile/o1_mf_sysaux_%u_.dbf
channel ORA_AUX_DISK_1: reading from backup piece /u01/backup/zzh_full_022t8fks_1_1.bkp
channel ORA_AUX_DISK_1: piece handle=/u01/backup/zzh_full_022t8fks_1_1.bkp tag=TAG20240613T110604
channel ORA_AUX_DISK_1: restored backup piece 1
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:01:45
Finished restore at 2024-06-13 11:14:15
datafile 1 switched to datafile copy
input datafile copy RECID=4 STAMP=1171538055 file name=/u01/dump/ORCL/datafile/o1_mf_system_m6nrwybv_.dbf
datafile 4 switched to datafile copy
input datafile copy RECID=5 STAMP=1171538055 file name=/u01/dump/ORCL/datafile/o1_mf_undotbs1_m6nrwyhw_.dbf
datafile 3 switched to datafile copy
input datafile copy RECID=6 STAMP=1171538055 file name=/u01/dump/ORCL/datafile/o1_mf_sysaux_m6nrwygk_.dbf
contents of Memory Script:
{
# set requested point in time
set until time "to_date('2024-06-13 11:10:10','yyyy-mm-dd hh24:mi:ss')";
# online the datafiles restored or switched
sql clone "alter database datafile 1 online";
sql clone "alter database datafile 4 online";
sql clone "alter database datafile 3 online";
# recover and open database read only
recover clone database tablespace "SYSTEM", "UNDOTBS1", "SYSAUX";
sql clone 'alter database open read only';
}
executing Memory Script
executing command: SET until clause
sql statement: alter database datafile 1 online
sql statement: alter database datafile 4 online
sql statement: alter database datafile 3 online
Starting recover at 2024-06-13 11:14:15
using channel ORA_AUX_DISK_1
starting media recovery
archived log for thread 1 with sequence 6 is already on disk as file /u01/app/archivelog/1_6_1171535158.dbf
archived log for thread 1 with sequence 7 is already on disk as file /u01/app/archivelog/1_7_1171535158.dbf
archived log file name=/u01/app/archivelog/1_6_1171535158.dbf thread=1 sequence=6
archived log file name=/u01/app/archivelog/1_7_1171535158.dbf thread=1 sequence=7
media recovery complete, elapsed time: 00:00:01
Finished recover at 2024-06-13 11:14:18
sql statement: alter database open read only
contents of Memory Script:
{
sql clone "create spfile from memory";
shutdown clone immediate;
startup clone nomount;
sql clone "alter system set control_files =
''/u01/dump/ORCL/controlfile/o1_mf_m6nrwr5f_.ctl'' comment=
''RMAN set'' scope=spfile";
shutdown clone immediate;
startup clone nomount;
# mount database
sql clone 'alter database mount clone database';
}
executing Memory Script
sql statement: create spfile from memory
database closed
database dismounted
Oracle instance shut down
connected to auxiliary database (not started)
Oracle instance started
Total System Global Area 6442448984 bytes
Fixed Size 8910936 bytes
Variable Size 1107296256 bytes
Database Buffers 5318377472 bytes
Redo Buffers 7864320 bytes
sql statement: alter system set control_files = ''/u01/dump/ORCL/controlfile/o1_mf_m6nrwr5f_.ctl'' comment= ''RMAN set'' scope=spfile
Oracle instance shut down
connected to auxiliary database (not started)
Oracle instance started
Total System Global Area 6442448984 bytes
Fixed Size 8910936 bytes
Variable Size 1107296256 bytes
Database Buffers 5318377472 bytes
Redo Buffers 7864320 bytes
sql statement: alter database mount clone database
contents of Memory Script:
{
# set requested point in time
set until time "to_date('2024-06-13 11:10:10','yyyy-mm-dd hh24:mi:ss')";
# set destinations for recovery set and auxiliary set datafiles
set newname for datafile 7 to new;
# restore the tablespaces in the recovery set and the auxiliary set
restore clone datafile 7;
switch clone datafile all;
}
executing Memory Script
executing command: SET until clause
executing command: SET NEWNAME
Starting restore at 2024-06-13 11:15:32
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: SID=129 device type=DISK
channel ORA_AUX_DISK_1: starting datafile backup set restore
channel ORA_AUX_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_AUX_DISK_1: restoring datafile 00007 to /u01/dump/PEPF_PITR_ORCL/datafile/o1_mf_users_%u_.dbf
channel ORA_AUX_DISK_1: reading from backup piece /u01/backup/zzh_full_022t8fks_1_1.bkp
channel ORA_AUX_DISK_1: piece handle=/u01/backup/zzh_full_022t8fks_1_1.bkp tag=TAG20240613T110604
channel ORA_AUX_DISK_1: restored backup piece 1
channel ORA_AUX_DISK_1: restore complete, elapsed time: 00:00:01
Finished restore at 2024-06-13 11:15:33
datafile 7 switched to datafile copy
input datafile copy RECID=8 STAMP=1171538133 file name=/u01/dump/PEPF_PITR_ORCL/datafile/o1_mf_users_m6ns2npg_.dbf
contents of Memory Script:
{
# set requested point in time
set until time "to_date('2024-06-13 11:10:10','yyyy-mm-dd hh24:mi:ss')";
# online the datafiles restored or switched
sql clone "alter database datafile 7 online";
# recover and open resetlogs
recover clone database tablespace "USERS", "SYSTEM", "UNDOTBS1", "SYSAUX" delete archivelog;
alter clone database open resetlogs;
}
executing Memory Script
executing command: SET until clause
sql statement: alter database datafile 7 online
Starting recover at 2024-06-13 11:15:33
using channel ORA_AUX_DISK_1
starting media recovery
archived log for thread 1 with sequence 6 is already on disk as file /u01/app/archivelog/1_6_1171535158.dbf
archived log for thread 1 with sequence 7 is already on disk as file /u01/app/archivelog/1_7_1171535158.dbf
archived log file name=/u01/app/archivelog/1_6_1171535158.dbf thread=1 sequence=6
archived log file name=/u01/app/archivelog/1_7_1171535158.dbf thread=1 sequence=7
media recovery complete, elapsed time: 00:00:01
Finished recover at 2024-06-13 11:15:36
database opened
contents of Memory Script:
{
# create directory for datapump import
sql "create or replace directory TSPITR_DIROBJ_DPDIR as ''
/u01/dump''";
# create directory for datapump export
sql clone "create or replace directory TSPITR_DIROBJ_DPDIR as ''
/u01/dump''";
}
executing Memory Script
sql statement: create or replace directory TSPITR_DIROBJ_DPDIR as ''/u01/dump''
sql statement: create or replace directory TSPITR_DIROBJ_DPDIR as ''/u01/dump''
Performing export of tables...
EXPDP> Starting "SYS"."TSPITR_EXP_pEpF_nBqn":
EXPDP> Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
EXPDP> Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
EXPDP> Processing object type TABLE_EXPORT/TABLE/STATISTICS/MARKER
EXPDP> Processing object type TABLE_EXPORT/TABLE/TABLE
EXPDP> . . exported "ZZH"."OBJ_TB" 9.543 MB 72373 rows
EXPDP> Master table "SYS"."TSPITR_EXP_pEpF_nBqn" successfully loaded/unloaded
EXPDP> ******************************************************************************
EXPDP> Dump file set for SYS.TSPITR_EXP_pEpF_nBqn is:
EXPDP> /u01/dump/tspitr_pEpF_92746.dmp
EXPDP> Job "SYS"."TSPITR_EXP_pEpF_nBqn" successfully completed at Thu Jun 13 11:16:11 2024 elapsed 0 00:00:22
Export completed
contents of Memory Script:
{
# shutdown clone before import
shutdown clone abort
}
executing Memory Script
Oracle instance shut down
Performing import of tables...
IMPDP> Master table "SYS"."TSPITR_IMP_pEpF_Blkh" successfully loaded/unloaded
IMPDP> Starting "SYS"."TSPITR_IMP_pEpF_Blkh":
IMPDP> Processing object type TABLE_EXPORT/TABLE/TABLE
IMPDP> Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
IMPDP> . . imported "ZZH"."OBJ_TB" 9.543 MB 72373 rows
IMPDP> Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
IMPDP> Processing object type TABLE_EXPORT/TABLE/STATISTICS/MARKER
IMPDP> Job "SYS"."TSPITR_IMP_pEpF_Blkh" successfully completed at Thu Jun 13 11:16:44 2024 elapsed 0 00:00:25
Import completed
Removing automatic instance
Automatic instance removed
auxiliary instance file /u01/dump/ORCL/datafile/o1_mf_temp_m6ns0c2n_.tmp deleted
auxiliary instance file /u01/dump/PEPF_PITR_ORCL/onlinelog/o1_mf_3_m6ns2rcv_.log deleted
auxiliary instance file /u01/dump/PEPF_PITR_ORCL/onlinelog/o1_mf_2_m6ns2rb4_.log deleted
auxiliary instance file /u01/dump/PEPF_PITR_ORCL/onlinelog/o1_mf_1_m6ns2r8p_.log deleted
auxiliary instance file /u01/dump/PEPF_PITR_ORCL/datafile/o1_mf_users_m6ns2npg_.dbf deleted
auxiliary instance file /u01/dump/ORCL/datafile/o1_mf_sysaux_m6nrwygk_.dbf deleted
auxiliary instance file /u01/dump/ORCL/datafile/o1_mf_undotbs1_m6nrwyhw_.dbf deleted
auxiliary instance file /u01/dump/ORCL/datafile/o1_mf_system_m6nrwybv_.dbf deleted
auxiliary instance file /u01/dump/ORCL/controlfile/o1_mf_m6nrwr5f_.ctl deleted
auxiliary instance file tspitr_pEpF_92746.dmp deleted
Finished recover at 2024-06-13 11:16:46
RMAN>
5、RMAN成功后查询并验证表是否恢复
SQL> select count(*) from obj_tb;
COUNT(*)
----------
72373
经过验证被误删除的表成功恢复。
相关文章：
Oracle 19C 数据库表被误删除的模拟恢复
Oracle 19C 数据库表被误删除的模拟恢复操作 1、模拟创建表用于恢复测试 sqlplus zzh/zzh SQL> create table obj_tb tablespace users as select * from dba_objects; Table created. SQL> select count(*) from obj_tb; COUNT(*) ---------- 72373 2、记录当前…...
【CICID】GitHub-Actions语法
[TOC] 【CICID】GitHub-Actions语法 1 场景 当我们开发过程中，经常需要提交代码，打包，部署新代码到对应的环境，整个过程都是人工手动操作，占据开发人员大量时间，并且很繁琐容易出错。所以需要借助一些…...
Ionic 创建 APP
Ionic 创建 APP Ionic 是一个强大的开源框架，用于构建高性能、高质量的移动和网页应用程序。它结合了 Angular、React 或 Vue 的强大功能，以及 Capacitor 或 Cordova 的原生功能，使得开发者可以轻松地创建跨平台的应用程序。本篇文章将指导您如何使用 Ionic 创建一个基本的…...
【数学代码】幂
Hello!大家好，我是学霸小羊，今天来讲讲幂。 求几个相同因数的积的运算，叫做乘方，乘方的结果叫做幂。 a^n，读作 “ a的n次方 ” 或 “ a的n次方幂”，a叫做底数，n叫做指数。 对于底数、指数和幂…...
 函数)
os.system() 函数
os.system() 是 Python 标准库 os 模块中的一个函数，用于在子终端中运行系统命令。它可以在 Python 脚本中调用外部命令或程序。具体来说，它通过执行命令字符串并返回执行状态来实现这一点。下面是对 os.system() 函数的详细解释： import os…...
Spring Boot中的RESTful API详细介绍及使用
在Spring Boot中，RESTful API的实现通过控制器类中的方法和特定的注解来完成。每个注解对应不同的HTTP请求方法，并通过处理请求参数和返回响应来实现不同的操作。 下面将详细解释RESTful API中的各个方面，包括GetMapping, PostMapping, PutMa…...
nlp学习笔记
目录 很多入门例子 bert chinese 很多入门例子 https://github.com/lansinuote/Huggingface_Toturials bert chinese import torch import torch.nn as nn from transformers import AutoTokenizer, AutoModel, BertModel, TFBertModel, BertTokenizer# youpath = D:/bert-…...
使用python获取内存信息
#!/usr/bin/python # -*- coding:utf-8 -*- psutil模块是一个跨平台的获取进程和系统应用情况（CPU，内存，磁盘，网络，传感器）的库。 该模块用于系统监控、限制进程资源和运行进程的管理等方面。 内存信息&am…...
外包公司泛滥，这些常识你应该提前知道？
今年大环境确实很不好 很多985,211的应届生都在网上大吐苦水，很多大龄离职大厂的技术人也好，业务人也好，都纷纷转向短视频平台做起了自媒体。而找工作的人普遍发现，某最火的招聘平台几乎都被外包公司刷屏了。大大小小的外包公司如…...
Linux下的抓包工具使用介绍
应用层 传输层 网络层 数据链路层 物理层 1）tcpdump（传输／网络层） tcpdump -i eth0 tcpdump -i eth0 -vnn -v：显示包含有TTL，TOS值等等更详细的信息 -n：不要做IP解析为主机名 -nn：…...
centos环境上：k8s 简单安装教程
本次演示安装3节点k8s环境，无需多言，直接上操作步骤： 1、环境准备 k8s部署前，首先需要准备好环境，除了1.4 步骤，其他步骤在所有（3个）节点上都要执行： 1.1 关闭防火墙 s…...
短视频矩阵系统/源码搭建---拆解热门视频功能开发上线
短视频矩阵系统/源码搭建 一、短视频矩阵系统源码开发需要用到以下技术： 1.前端技术：HTML、CSS、JavaScript、Vue.js等前端框架。 2.后端技术：Java、Python、PHP等后端语言及相关框架，如Spring Boot、Django、Laravel等。 3.移…...
手机和模拟器的 Frida 环境配置
目录 一、配置 JDK 和 android 环境 二、连接设备和查看权限 1、连接设备 2、查看手机权限 三、手机配置 Frida 1、frida-server下载 2、验证 四、模拟器配置 Frida 1、下载模拟器并调节成手机版： 2、连接并查看架构 3、配置并开启 x86 的 frida-serve…...
力扣1385.两个数组间的距离值
力扣1385.两个数组间的距离值 二分判断答案是否正确 class Solution {public:int findTheDistanceValue(vector<int>& arr1, vector<int>& arr2, int d) {ranges::sort(arr2);ranges::sort(arr1);int m arr2.size();auto check [&](int low,int h…...
[C++] 小游戏 斗破苍穹 2.11.6 版本 zty出品
大家好，今天zty带来的是斗破苍穹的 2.11.6 版本，这个版本主要更新了：1、背包 2、将退出游戏改到了设置里面 3、如果不逃跑不会停止战斗。废话不多说， 先赞后看 养成习惯 code #include<stdio.h> #include<iostrea…...
认识与学习JSP
JSP核心技术 什么是JSP JSP全称是Java Server Pages，它和servle技术一样，都是SUN公司定义的一种用于开发动态web资源的技术。JSP/Servlet规范。JSP实际上就是Servlet JSP这门技术的最大的特点在于，写jsp就像在写html，但它相比htm…...
MySql 各种 join
MySql 定义了很多join的方式，接下来我们用一个例子来讲解。 用到的表 本文用到了两个表s1,s2： 内外连接 测试 1 1 1.select * from s1 inner join s2 on(s1.id s2.id);： -------- | id | id | -------- | 3 | 3 | | 4 | 4 | --------2…...
【Android面试八股文】Android中操作多线程的方式有哪些?
文章目录 1. 使用 `Thread` 和 `Runnable`2. `AsyncTask`3. `Handler` 和 `Looper`4. `HandlerThread`5. `ThreadPoolExecutor`6. `IntentService`7. `RxJava`8. `Coroutine`（协程）9. `WorkManager`在Android开发中，有多种方式可以进行多线程操作。以下是主要的几种方式： 1…...
语义分割和目标检测的关系
目录 1.语义分割的目标 2.目标检测的目标 3.两种任务的异同之处 从大方向的任务特点上来说 （1）物体的位置 （2）物体的分类 从数据格式来说 (1）语义分割的数据格式 (2）目标检测的数据格式 1.语义分…...
SpringBoot 大文件基于md5实现分片上传、断点续传、秒传
SpringBoot 大文件基于md5实现分片上传、断点续传、秒传 SpringBoot 大文件基于md5实现分片上传、断点续传、秒传前言1. 基本概念1.1 分片上传1.2 断点续传1.3 秒传1.4 分片上传的实现 2. 分片上传前端实现2.1 什么是WebUploader？功能特点接口说明事件APIHook 机制 …...
从WWDC看苹果产品发展的规律
WWDC 是苹果公司一年一度面向全球开发者的盛会，其主题演讲展现了苹果在产品设计、技术路线、用户体验和生态系统构建上的核心理念与演进脉络。我们借助 ChatGPT Deep Research 工具，对过去十年 WWDC 主题演讲内容进行了系统化分析，形成了这份…...
练习（含atoi的模拟实现,自定义类型等练习）
一、结构体大小的计算及位段 （结构体大小计算及位段 详解请看：自定义类型：结构体进阶-CSDN博客） 1.在32位系统环境，编译选项为4字节对齐，那么sizeof(A)和sizeof(B)是多少？ #pragma pack(4)st…...
第 86 场周赛：矩阵中的幻方、钥匙和房间、将数组拆分成斐波那契序列、猜猜这个单词
Q1、[中等] 矩阵中的幻方 1、题目描述 3 x 3 的幻方是一个填充有 从 1 到 9 的不同数字的 3 x 3 矩阵，其中每行，每列以及两条对角线上的各数之和都相等。 给定一个由整数组成的row x col 的 grid，其中有多少个 3 3 的 “幻方” 子矩阵&am…...
ABAP设计模式之---“简单设计原则(Simple Design)”
“Simple Design”（简单设计）是软件开发中的一个重要理念，倡导以最简单的方式实现软件功能，以确保代码清晰易懂、易维护，并在项目需求变化时能够快速适应。 其核心目标是避免复杂和过度设计，遵循“让事情保…...
【无标题】路径问题的革命性重构：基于二维拓扑收缩色动力学模型的零点隧穿理论
路径问题的革命性重构：基于二维拓扑收缩色动力学模型的零点隧穿理论 一、传统路径模型的根本缺陷 在经典正方形路径问题中（图1）： mermaid graph LR A((A)) --- B((B)) B --- C((C)) C --- D((D)) D --- A A -.- C[无直接路径] B -…...
LRU 缓存机制详解与实现（Java版） + 力扣解决
📌 LRU 缓存机制详解与实现（Java版） 一、📖 问题背景 在日常开发中，我们经常会使用 缓存（Cache） 来提升性能。但由于内存有限，缓存不可能无限增长，于是需要策略决定&am…...
Axure 下拉框联动
实现选省、选完省之后选对应省份下的市区...
OpenGL-什么是软OpenGL/软渲染/软光栅？
软OpenGL（Software OpenGL）或者软渲染指完全通过CPU模拟实现的OpenGL渲染方式（包括几何处理、光栅化、着色等），不依赖GPU硬件加速。这种模式通常性能较低，但兼容性极强，常用于不支持硬件加速…...
深入理解 C++ 左值右值、std::move 与函数重载中的参数传递
在 C 编程中，左值和右值的概念以及std::move的使用，常常让开发者感到困惑。特别是在函数重载场景下，如何合理利用这些特性来优化代码性能、确保语义正确，更是一个值得深入探讨的话题。 在开始之前，先提出几个问题&…...
后端下载限速（redis记录实时并发，bucket4j动态限速）
✅ 使用 Redis 记录 所有用户的实时并发下载数✅ 使用 Bucket4j 实现 全局下载速率限制（动态）✅ 支持 动态调整限速策略✅ 下载接口安全、稳定、可监控 🧩 整体架构概览 模块功能Redis存储全局并发数和带宽令牌桶状态Bucket4j Redis分布式限…...