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Tuning MySQL

shantanuo — Fri, 04 Sep 2015 15:34:02 GMT

Getting the shell script:wget launchpadlibrarian.net

Running:sh tuning-primer.sh

Check for table corruption quick and fast

shantanuo — Mon, 13 May 2013 15:39:57 GMT

#!/bin/sh

for dbname in mysqlshow | awk '{print $2}'domysqlcheck $dbname ticket -Fqdone

call this shell script and find the errors

time sh check.sh | grep error

shell script example

shantanuo — Wed, 09 Feb 2011 04:46:25 GMT

An example of shell script.This will print numbers 0 to 500 in one line.

#!/bin/bashZ=0LIMIT=500while [ "$Z" -lt "$LIMIT" ]

doecho -n "$Z... "Z=$( expr $Z + 1 )doneechoexit 0

ping the address received from positional parameter

#!/bin/bash

if [ $# -eq 0 ]thenSITE="google.com"elseSITE="$1"fi

ping -c 2 $SITE > /dev/nullif [ $? != 0 ]thenecho $(date +%F) ... Network Failure!fi

Here is the script that will loop two thousand times and print the statement on the screen.

#!/bin/sh

MAX=2000i=1echo " truncate table t1; "

while [ $i -le $MAX ]doecho " insert into t1(f1) values($i); "i=expr $i + 1done

Match Operator in AWK

shantanuo — Wed, 09 Feb 2011 04:40:36 GMT

The match operator is the tilde “~” which will match an expression in a record or field. In this example awk is used to search for a field, number 7, that matches “nologin”.

awk -F: '$7 ~ /nologin/' /etc/passwdbin:x:1:1:bin:/bin:/sbin/nologindaemon:x:2:2:daemon:/sbin:/sbin/nologinadm:x:3:4:adm:/var/adm:/sbin/nologin

Copy table

shantanuo — Tue, 28 Dec 2010 05:28:10 GMT

#!/bin/shfor i in find /var/lib/mysql/test/ -name "Table1.*"docp $i dirname $i'/test'basename $idone

duplicate a table Table1 by coping the files if it is a MyISAM table.

Brace Expansion

shantanuo — Sat, 12 Jun 2010 13:16:45 GMT

Brace expansion is used to generate arbitrary strings. For e.g.ls mysql*.0000{1..3}

will list the files like mysql.00001 mysql.00002 & mysql.00003

This can also be used for something like this...

cp mysql.log{,.bak}

cp mysql.log mysql.log.bak

cp $da.log{.bak,}

cp 2010-05-28.log.bak 2010-05-28.log

User input in shell script

shantanuo — Wed, 24 Mar 2010 12:09:33 GMT

#!/bin/shunset REPLYuntil [[ $REPLY ]]; do read -p "Enter your name: "doneecho "welcome $REPLY"

Inernal File Separator

shantanuo — Tue, 01 Dec 2009 11:37:01 GMT

The safe way to change IFS in a 'while read' loop is:

while IFS=| read a b cdo: whateverdone

valid date

shantanuo — Mon, 13 Apr 2009 10:14:50 GMT

validdate.sh script will look like this...

#!/bin/shuserdate=$1date -d $userdate &> /dev/nullif [ $? -ne 0 ] ; thenecho You entered an invalid date, $userdateelseecho The date $userdate is validfi

sh validdate.sh 2009-33-44

You entered an invalid date, 2009-33-44

better code

shantanuo — Tue, 10 Mar 2009 12:45:27 GMT

test -s /var/log/mailme.txtif [[ $? -eq 0 ]] ; thenThe above 2 lines can be written in one line as shown below:

if [[ -z /var/log/mailme.txt ]]; then