=====================================

-- :: 0x7f305b965700 INNODB MONITOR OUTPUT

=====================================

Per second averages calculated from the last  seconds

-----------------

BACKGROUND THREAD

-----------------

srv_master_thread loops:  srv_active,  srv_shutdown,  srv_idle

srv_master_thread log flush and writes:

----------

SEMAPHORES

----------

OS WAIT ARRAY INFO: reservation count

--Thread  has waited at buf0buf.cc line  for 0.00 seconds the semaphore:

Mutex at 0x3cc9ce8, Mutex BUF_POOL created buf0buf.cc:, lock var 

--Thread  has waited at buf0buf.cc line  for 0.00 seconds the semaphore:

Mutex at 0x3cc9ce8, Mutex BUF_POOL created buf0buf.cc:, lock var 

--Thread  has waited at buf0buf.cc line  for 0.00 seconds the semaphore:

Mutex at 0x3cc9ce8, Mutex BUF_POOL created buf0buf.cc:, lock var 

--Thread  has waited at buf0flu.cc line  for 0.00 seconds the semaphore:

Mutex at 0x3cc9ce8, Mutex BUF_POOL created buf0buf.cc:, lock var 

OS WAIT ARRAY INFO: signal count

RW-shared spins , rounds , OS waits

RW-excl spins , rounds , OS waits

RW-sx spins , rounds , OS waits

Spin rounds per wait: 2190803016.00 RW-shared, 4078639377.00 RW-excl, 18.78 RW-sx

------------------------

LATEST DETECTED DEADLOCK

------------------------

-- :: 0x7f3059d36700

*** () TRANSACTION:

TRANSACTION , ACTIVE  sec starting index read

mysql tables in use , locked

LOCK WAIT  lock struct(s), heap size ,  row lock(s)

MySQL thread id , OS thread handle , query id  10.50.12.12 root updating

update tbl_ec_document set ISSUED=,ISSUE_ERR_MSG='Error on line -1: Premature end of file.' where FPQQLSH='1t8gN9RLxTQT1AD4kQcX'

*** () WAITING FOR THIS LOCK TO BE GRANTED:

RECORD LOCKS space id  page no  n bits  index PRIMARY of table `SAJT_DZFP_PT`.`tbl_ec_document` trx id  lock_mode X locks rec but not gap waiting

Record lock, heap no  PHYSICAL RECORD: n_fields ; compact format; info bits

 : len ; hex 317438674e39524c78545154314144346b516358; asc 1t8gN9RLxTQT1AD4kQcX;;

 : len ; hex 000002404efb; asc    @N ;;

 : len ; hex 4000004aa8272b; asc @  J '+;;

 : len ; hex ; asc  s;;

 : len ; hex 323031372d30382d30322031333a30303a3030; asc -- ::;;

 : len ; hex ; asc         ;;

 : len ; hex ; asc         ;;

 : len ; hex 4572726f72206f6e206c696e65202d313a205072656d617475726520656e; asc Error on line -: Premature en; (total  bytes);

 : len ; hex ; asc 51310000501771313R;;

 : len ; hex e4b88ae6b5b7e5b882e68aa4e79086e5ada6e4bc9a; asc                      ;;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : len ; hex 31322e30; asc 12.0;;

 : len ; hex ; asc 51310000501771313R;;

 : len ; hex e4b88ae6b5b7e5b882e68aa4e79086e5ada6e4bc9a; asc                      ;;

 : len ; hex e4b88ae6b5b7e5b882e99d99e5ae89e58cbae58c97e4baace8a5bfe8b7af; asc                               ; (total  bytes);

 : len ; hex ; asc ;;

 : len ; hex e5b7a5e8a18ce4b88ae6b5b7e5b882e99d99e5ae89e5afbae694afe8a18c; asc                               ; (total  bytes);

 : len ; hex e5a48de697a6e5a4a7e5ada6e99984e5b19ee98791e5b1b1e58cbbe999a2; asc                               ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex 313532313131373030313640667564616e2e6564752e636e; asc @fudan.edu.cn;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

 : len ; hex e9bb84e788b1e58d8e; asc          ;;

 : SQL NULL;

 : SQL NULL;

 : len ; hex ; asc         ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : len ; hex e694afe4bb98e5ae9d; asc          ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex 3133315130364e4f; asc 131Q06NO;;

 : len ; hex 999d44de68; asc   D h;;

 : len ; hex ; asc         ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc 3f7385874fdf4cbb8550dfe0e38e7b; (total  bytes);

 : len ; hex 5348484c5848; asc SHHLXH;;

 : len ; hex ; asc SH;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

*** () TRANSACTION:

TRANSACTION , ACTIVE  sec starting index read

mysql tables in use , locked

 lock struct(s), heap size ,  row lock(s)

MySQL thread id , OS thread handle , query id  10.50.12.12 root updating

update tbl_ec_document set ISSUED=,ISSUE_ERR_MSG='Error on line -1: Premature end of file.' where FPQQLSH='1t8gN9RLxTQT1AD4kQcX'

*** () HOLDS THE LOCK(S):

RECORD LOCKS space id  page no  n bits  index PRIMARY of table `SAJT_DZFP_PT`.`tbl_ec_document` trx id  lock mode S locks rec but not gap

Record lock, heap no  PHYSICAL RECORD: n_fields ; compact format; info bits

 : len ; hex 317438674e39524c78545154314144346b516358; asc 1t8gN9RLxTQT1AD4kQcX;;

 : len ; hex 000002404efb; asc    @N ;;

 : len ; hex 4000004aa8272b; asc @  J '+;;

 : len ; hex ; asc  s;;

 : len ; hex 323031372d30382d30322031333a30303a3030; asc -- ::;;

 : len ; hex ; asc         ;;

 : len ; hex ; asc         ;;

 : len ; hex 4572726f72206f6e206c696e65202d313a205072656d617475726520656e; asc Error on line -: Premature en; (total  bytes);

 : len ; hex ; asc 51310000501771313R;;

 : len ; hex e4b88ae6b5b7e5b882e68aa4e79086e5ada6e4bc9a; asc                      ;;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : len ; hex 31322e30; asc 12.0;;

 : len ; hex ; asc 51310000501771313R;;

 : len ; hex e4b88ae6b5b7e5b882e68aa4e79086e5ada6e4bc9a; asc                      ;;

 : len ; hex e4b88ae6b5b7e5b882e99d99e5ae89e58cbae58c97e4baace8a5bfe8b7af; asc                               ; (total  bytes);

 : len ; hex ; asc ;;

 : len ; hex e5b7a5e8a18ce4b88ae6b5b7e5b882e99d99e5ae89e5afbae694afe8a18c; asc                               ; (total  bytes);

 : len ; hex e5a48de697a6e5a4a7e5ada6e99984e5b19ee98791e5b1b1e58cbbe999a2; asc                               ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex 313532313131373030313640667564616e2e6564752e636e; asc @fudan.edu.cn;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

 : len ; hex e9bb84e788b1e58d8e; asc          ;;

 : SQL NULL;

 : SQL NULL;

 : len ; hex ; asc         ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : len ; hex e694afe4bb98e5ae9d; asc          ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex 3133315130364e4f; asc 131Q06NO;;

 : len ; hex 999d44de68; asc   D h;;

 : len ; hex ; asc         ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc 3f7385874fdf4cbb8550dfe0e38e7b; (total  bytes);

 : len ; hex 5348484c5848; asc SHHLXH;;

 : len ; hex ; asc SH;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

*** () WAITING FOR THIS LOCK TO BE GRANTED:

RECORD LOCKS space id  page no  n bits  index PRIMARY of table `SAJT_DZFP_PT`.`tbl_ec_document` trx id  lock_mode X locks rec but not gap waiting

Record lock, heap no  PHYSICAL RECORD: n_fields ; compact format; info bits

 : len ; hex 317438674e39524c78545154314144346b516358; asc 1t8gN9RLxTQT1AD4kQcX;;

 : len ; hex 000002404efb; asc    @N ;;

 : len ; hex 4000004aa8272b; asc @  J '+;;

 : len ; hex ; asc  s;;

 : len ; hex 323031372d30382d30322031333a30303a3030; asc -- ::;;

 : len ; hex ; asc         ;;

 : len ; hex ; asc         ;;

 : len ; hex 4572726f72206f6e206c696e65202d313a205072656d617475726520656e; asc Error on line -: Premature en; (total  bytes);

 : len ; hex ; asc 51310000501771313R;;

 : len ; hex e4b88ae6b5b7e5b882e68aa4e79086e5ada6e4bc9a; asc                      ;;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : len ; hex 31322e30; asc 12.0;;

 : len ; hex ; asc 51310000501771313R;;

 : len ; hex e4b88ae6b5b7e5b882e68aa4e79086e5ada6e4bc9a; asc                      ;;

 : len ; hex e4b88ae6b5b7e5b882e99d99e5ae89e58cbae58c97e4baace8a5bfe8b7af; asc                               ; (total  bytes);

 : len ; hex ; asc ;;

 : len ; hex e5b7a5e8a18ce4b88ae6b5b7e5b882e99d99e5ae89e5afbae694afe8a18c; asc                               ; (total  bytes);

 : len ; hex e5a48de697a6e5a4a7e5ada6e99984e5b19ee98791e5b1b1e58cbbe999a2; asc                               ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex 313532313131373030313640667564616e2e6564752e636e; asc @fudan.edu.cn;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

 : len ; hex e9bb84e788b1e58d8e; asc          ;;

 : SQL NULL;

 : SQL NULL;

 : len ; hex ; asc         ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : SQL NULL;

 : len ; hex e694afe4bb98e5ae9d; asc          ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex 3133315130364e4f; asc 131Q06NO;;

 : len ; hex 999d44de68; asc   D h;;

 : len ; hex ; asc         ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc 3f7385874fdf4cbb8550dfe0e38e7b; (total  bytes);

 : len ; hex 5348484c5848; asc SHHLXH;;

 : len ; hex ; asc SH;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : len ; hex ; asc ;;

 : SQL NULL;

 : SQL NULL;

*** WE ROLL BACK TRANSACTION ()

------------

TRANSACTIONS

------------

Trx id counter

Purge done for trx's n:o < 41115613 undo n:o < 0 state: running but idle

History list length

LIST OF TRANSACTIONS FOR EACH SESSION:

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

---TRANSACTION , not started

 lock struct(s), heap size ,  row lock(s)

--------

FILE I/O　　//IO Thread 
　　　　　　 //params: innodb_read_io_threads, innodb_write_io_threads

--------

I/O thread  state: waiting for completed aio requests (insert buffer thread)

I/O thread  state: waiting for completed aio requests (log thread)

I/O thread  state: waiting for completed aio requests (read thread)

I/O thread  state: waiting for completed aio requests (read thread)

I/O thread  state: waiting for completed aio requests (read thread)

I/O thread  state: waiting for completed aio requests (read thread)

I/O thread  state: waiting for completed aio requests (write thread)

I/O thread  state: waiting for completed aio requests (write thread)

I/O thread  state: waiting for completed aio requests (write thread)

I/O thread  state: complete io for buf page (write thread)

Pending normal aio reads: [, , , ] , aio writes: [, , , ] ,

 ibuf aio reads:, log i/o's:, sync i/o's:

Pending flushes (fsync) log: ; buffer pool:

 OS file reads,  OS file writes,  OS fsyncs

20542.79 reads/s,  avg bytes/read, 26.02 writes/s, 10.93 fsyncs/s

-------------------------------------

INSERT BUFFER AND ADAPTIVE HASH INDEX

-------------------------------------

Ibuf: size ,       //已经合并记录页的数量
free list len ,  //空闲列表长度
seg size ,       //当前 Insert Buffer 的大小为 241 * 16K
 merges     //合并次数
/*
　　insert 表示 Insert Buffer
   delete mark 表示 Delete Buffer
   delete 表示 Purge Buffer
   discarded operaations 表示当 Change Buffer 发生 merge 时，表已经被删除，此时就无需再将记录合并到辅助索引中了
*/

merged operations:

 insert , delete mark , delete

discarded operations:

 insert , delete mark , delete

Hash table size , node heap has  buffer(s)

Hash table size , node heap has  buffer(s)

Hash table size , node heap has  buffer(s)

Hash table size , node heap has  buffer(s)

Hash table size , node heap has  buffer(s)

Hash table size , node heap has  buffer(s)

Hash table size , node heap has  buffer(s)

Hash table size , node heap has  buffer(s)

140.36 hash searches/s, 69.93 non-hash searches/s  //自适应哈希索引 AHI

---

LOG　　//checkpoint 技术，重做日志

---

Log sequence number

Log flushed up to

Pages flushed up to

Last checkpoint at

 pending log flushes,  pending chkp writes

 log i/o's done, 4.68 log i/o's/second

----------------------

BUFFER POOL AND MEMORY

----------------------

Total large memory allocated

Dictionary memory allocated

Buffer pool size   8191  //当前 buffer pool size 共有 8191个页，即 8191 * 16k = 约 128 M 的缓冲池

Free buffers       5　　　//当前 Free 列表中页的数量　

Database pages     8174  //LRU 列表中的数量
　　　　　　　　　　　　　　 // Buffer pool size = Free buffers + Database pages + (自适应哈希索引，Lock信息，Insert Buffer 等等)

Old database pages

Modified db pages

Pending reads

Pending writes: LRU , flush list , single page

Pages made young ,  //LRU 列表中页移动到前端的次数
not young 312454897572       //因 innodb_old_blocks_time 的设置而导致页没有从 old 部分移动到 new 部分的页

6.88 youngs/s, 79196.46 non-youngs/s

Pages read , created , written

20542.86 reads/s, 0.56 creates/s, 19.66 writes/s

Buffer pool hit rate  / ,  //缓冲池命中率
 young-making rate  /  not  /

Pages read ahead 182.65/s, evicted without access 77.27/s, Random read ahead 0.00/s

LRU len: , unzip_LRU len: 0  //LRU 列表中一共有 8174 个页，而 unzip_LRU 列表中有 0 个页，LRU 中的页包含了 unzip_LRU 列表中的页

I/O sum[]:cur[], unzip sum[]:cur[]

--------------

ROW OPERATIONS

--------------

 queries inside InnoDB,  queries in queue

 read views open inside InnoDB

Process ID=, Main thread ID=, state: sleeping

Number of rows inserted , updated , deleted , read

3.59 inserts/s, 1.41 updates/s, 0.02 deletes/s, 465657.94 reads/s

----------------------------

END OF INNODB MONITOR OUTPUT

============================

MySQL--SHOW ENGINE INNODB STATUS的更多相关文章

  1. show engine innodb status\G

    mysql> show engine innodb status\G *************************** 1. row *************************** ...

  2. InnoDB Monitors | SHOW ENGINE INNODB STATUS

    参考 <mysql 5.7手册>,15.17章节 InnoDB监视器提供有关InnoDB内部状态的信息. 这些信息对于性能调优非常有用.其实所谓的监视器,就是 show engine in ...

  3. show engine innodb status 输出结果解读

    show engine innodb status 输出结果解读 基于MySQL 5.7.32 最近想整理一下show engine innodb status的解读,但是发现中文互联网上相关的信息要 ...

  4. mysql之show engine innodb status解读

    注:以下内容为根据<高性能mysql第三版>和<mysql技术内幕innodb存储引擎>的innodb status部分的个人理解,如果有错误,还望指正!!   innodb存 ...

  5. mysql之show engine innodb status解读（转）

    add by zhj: 我第一次知道这个命令是线上服务出了问题,然后同事用这个命令去查看死锁.但用这个命令看死锁有一定的局限性,它只能看到最后一次死锁, 而且只能看到死锁环中的两个事务所执行的最后一条 ...

  6. mysql：innodb monitor（show engine innodb status）探秘

    在旧的版本里面是show innodb status命令,新版本后改动了一些:show engine innodb status; 我们最熟悉的,应当就是show innodb status命令,可以 ...

  7. show engine innodb status 详解

    找个mysql客户端,执行show engine innodb status得到如下结果: 详细信息如下: ************************************** ======= ...

  8. show engine innodb status解读

    xiaoboluo768   注:以下内容为根据<高性能mysql第三版>和<mysql技术内幕innodb存储引擎>的innodb status部分的个人理解,如果有错误,还 ...

  9. （Sqlyog或Navicat不友好处）SHOW ENGINE INNODB STATUS 结果为空或结果为=====================================

    因为最近在学习innodb引擎,所以就在自己的sqlyog上执行上述命令: SHOW ENGINE INNODB STATUS 结果显示如下: 换了个客户端navicat,执行如下: 最后登录到服务器 ...

  10. show engine innodb status 详细介绍

    Contents Header1 SEMAPHORES. 1 LATEST DETECTED DEADLOCK. 3 TRANSACTIONS. 5 什么是purge操作... 5 FILE I/O. ...

随机推荐

  1. （分治）输出前m大的数。。。

    描述给定一个数组包含n个元素,统计前m大的数并且把这m个数从大到小输出.输入第一行包含一个整数n,表示数组的大小.n < 100000.第二行包含n个整数,表示数组的元素,整数之间以一个空格分开 ...

  2. MSDN原版系统镜像ISO下载站

    官网 网址1:http://www.imsdn.cn/ Windows 10 最新版本 1909 正式版 ISO 镜像下载 (微软 MSDN / VL 官方原版系统) 网址2:https://www. ...

  3. 用JS改变embed标签的src属性

    思路: A.先隐藏embed标签 B.清除embed元素 C.为embed重新赋值,加入Html页面中 1.html代码 <object id="forfun" classi ...

  4. windows下java项目打包、启动批处理 .bat文件

    maven打包,脚本内容: @echo off echo 正在设置临时环境变量 set JAVA_HOME=C:\Program Files\Java\jdk1.6.0_45 set MAVEN_HO ...

  5. cf749 D. Leaving Auction

    #include<bits/stdc++.h> #define lowbit(x) x&(-x) #define LL long long #define N 200005 #de ...

  6. BZOJ 4853 [Jsoi2016]飞机调度

    题解: 我严重怀疑语文水平(自己的和出题人的) 把航线按照拓扑关系建立DAG 然后最小路径覆盖 为什么两条首尾相接航线之间不用维护???? #include<iostream> #incl ...

  7. C# 并行线程调用

    参考 一.异步委托开启线程 Action<int, int> a = add; a.BeginInvoke(, , null, null);//前两个是add方法的参数,后两个可以为空 C ...

  8. mark LINUX_6.8 python_2.6.6 setup版本升级 python 2.7.9 安装 pip 临时使用国内镜像源库 指定模块版本 删除指定模块

    简单但却又经常需要使用  网上  贴子也很多  也经常用  所以 做个mark 吧: 1首先下载python2.7.9 源tar包 源码安装 可利用linux自带下载工具wget下载,如下所示:   ...

  9. html 基础 （9.19 第八天）

    一.HTML:超文本标记语言,是一种标签语言,不是编程语言,显示数据有双标签<body></body> 和单标签<img src=# / >, 标签大小写都可以通过 ...

  10. HDU - 5976 Detachment（逆元）

    题意:将一个数x拆成a1+a2+a3+……,ai不等于aj,求最大的a1*a2*a3*……. 分析: 1.预处理前缀和前缀积,因为拆成1对乘积没有贡献,所以从2开始拆起. 2.找到一个id,使得2+3 ...