对DBA而言,经常碰到升级数据库或是apply patch,以及有些时候需要运行大量的脚本。对于这些操作我们希望现在在屏幕同时又输出的
对DBA而言,经常碰到升级数据库或是apply patch,,以及有些时候需要运行大量的脚本。对于这些操作我们希望现在在屏幕同时又输出的文件以备后续查询过程中曾经丢失的步骤或错误。Linux下的script命令就是解决这个问题的好帮手。
1、script命令描述
script命令会记录所有的操作到文件同时在屏幕上输出,直到终止登陆的会话,或使用CRTL+D,或使用exit退出则停止记录。
这个命令对于数据库的升级或是重要设置的情形下使用可以用于后续查询操作成功或失败。
用法: $ script [upgrade.log]
如果未指定日志文件名的情形,自动生成日志文件名为typescript。
如果需要输出到已经存在的日志文件,则使用 -a 参数,再接已经存在日志文件名。
如果需要在输出到日志文件的同时,也可以查看日志文件的内容,可以使用 -f 参数。
# script 帮助描述
robin@SZDB:~> man script
NAME
script - make typescript of terminal session
SYNOPSIS
script [-a] [-c COMMAND] [-f] [-q] [-t] [file]
DESCRIPTION
Script makes a typescript of everything printed on your terminal. It is useful for students who need a hardcopy record of
an interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1).
If the argument file is given, script saves all dialogue in file. If no file name is given, the typescript is saved in the
file typescript.
Options:
-a Append the output to file or typescript, retaining the prior contents.
-c COMMAND
Run the COMMAND rather than an interactive shell. This makes it easy for a script to capture the output of a pro-
gram that behaves differently when its stdout is not a tty.
-f Flush output after each write. This is nice for telecooperation: One person does `mkfifo foo; script -f foo' and
another can supervise real-time what is being done using `cat foo'.
-q Be quiet.
-t Output timeing data to standard error. This data contains two fields, separated by a space. The first field indi-
cates how much time elapsed since the previous output. The second field indicates how many characters were output
this time. This information can be used to replay typescripts with realistic typing and output delays.

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MySQLoffersvariousstorageengines,eachsuitedfordifferentusecases:1)InnoDBisidealforapplicationsneedingACIDcomplianceandhighconcurrency,supportingtransactionsandforeignkeys.2)MyISAMisbestforread-heavyworkloads,lackingtransactionsupport.3)Memoryengineis

Common security vulnerabilities in MySQL include SQL injection, weak passwords, improper permission configuration, and unupdated software. 1. SQL injection can be prevented by using preprocessing statements. 2. Weak passwords can be avoided by forcibly using strong password strategies. 3. Improper permission configuration can be resolved through regular review and adjustment of user permissions. 4. Unupdated software can be patched by regularly checking and updating the MySQL version.

Identifying slow queries in MySQL can be achieved by enabling slow query logs and setting thresholds. 1. Enable slow query logs and set thresholds. 2. View and analyze slow query log files, and use tools such as mysqldumpslow or pt-query-digest for in-depth analysis. 3. Optimizing slow queries can be achieved through index optimization, query rewriting and avoiding the use of SELECT*.


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