场景:有时候因为磁盘损坏或人为原因错误删除了磁盘中的二进制文件,导致mysql中的show binary logs记录和实际的物理磁盘中的二进制文件不匹配
#binlogdiff.sh
#!/bin/sh
#ocpyang@126.com
#作用:mysql中show binary logs记录的二进制日志文件和实际的物理文件比较,检查
#磁盘中对应的二进制日志文件是否有丢失
source /usr/local/mysql/scripts/mysql_env.ini
binlog_init=tmpinit.`date +%Y%m%d%H%M%S`.txt
binlog_midd=tmpmidd.`date +%Y%m%d%H%M%S`.txt #mysql中show binary logs记录的日志文件
binlog_res=tmpres.`date +%Y%m%d%H%M%S`.txt #binlog物理磁盘路径中的日志文件
my_cnf=/usr/local/mysql/my.cnf #mysql的配置文件
log_bin_path=`grep -i "^log-bin" $my_cnf |cut -d = -f 2`
log_bin=`dirname $log_bin_path`
#lookup binlog records in mysql
mysql -h${MYSQL_HOST} -u${MYSQL_USER} -p${MYSQL_PASS} -e"show binary logs;" >${binlog_init}
cat ${binlog_init} | cut -f 1 |cut -d . -f 2 |grep -i '^[0-9]' |sort -n >${binlog_midd}
#lookup binlog records in disk
ls -t ${log_bin}| grep '^mysql-bin' |cut -d . -f 2 |grep -i '^[0-9]' |sort -n >${binlog_res}
diff -c ${binlog_midd} $binlog_res
#clean temp file
rm -rf ${binlog_init}
rm -rf ${binlog_midd}
rm -rf ${binlog_res}

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No,youshouldnotusetherootuserinMySQLforyourproduct.Instead,createspecificuserswithlimitedprivilegestoenhancesecurityandperformance:1)Createanewuserwithastrongpassword,2)Grantonlynecessarypermissionstothisuser,3)Regularlyreviewandupdateuserpermissions

MySQLstringdatatypesshouldbechosenbasedondatacharacteristicsandusecases:1)UseCHARforfixed-lengthstringslikecountrycodes.2)UseVARCHARforvariable-lengthstringslikenames.3)UseBINARYorVARBINARYforbinarydatalikecryptographickeys.4)UseBLOBorTEXTforlargeuns


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