相信为数不少的系统管理员每天都在做着同一样的工作mdash;mdash;对数据进行备份。一旦哪一天疏忽了,而这一天系统又恰恰发
相信为数不少的系统管理员每天都在做着同一样的工作——对数据进行备份。一旦哪一天疏忽了,而这一天系统又恰恰发生了故障,需要进行数据恢复,那么此时就无能为力了。假如每天设定一个固定的时间,系统自动进行备份,那该多好啊!下面笔者结合实践经验,谈一谈UNIX环境下Oracle数据库的自动备份,以起到抛砖引玉的作用。
我们计划让数据库在晚上23点做export导出备份,在凌晨2点将备份文件拷贝到磁带上,在凌晨4点将备份文件拷贝到另一台UNIX机器上,为此我们可进行如下操作:
一、导出数据库
export命令将数据库中的数据备份成一个二进制文件,它通常有三种模式:用户模式、表模式和整个数据库模式。本文拟采用用户模式,备份之前,应先建立一个备份目录,以容纳备份文件,比如可建一个/backup目录。接着我们可在UNIX的Oracle目录下(也可以是其它目录)分别建立两个文件ora—backup,tar—backup。需要说明的是,前一个文件需要对Oracle的参数进行初始化,为了方便起见,我们不妨将初始化命令放到一个文件中(文件名姑且定为ora—env),再由第一个文件调用它。
1. ora—env文件对Oracle的参数进行初始化,其内容如下:
ORACLE—HOME=$ORACLE—HOME;export ORACLE—HOME
ORACLE—SID=ora73;export ORACLE—SID
ORACLE—TERM=sun;export ORACLE—TERM
LD—LIBRARY—PATH=$ORACLE—HOME/lib;export LD—LIBRARY—PATH
ORA—NLS32=$ORACLE—HOME/ocommon/nls/admin/data;export ORA—NLS
PATH=.:/usr/ccs/bin:/usr/ucb:$ORACLE—HOME/bin:$PATH;export PATH
DISPLAY=host1:0;export DISPLAY
NLS—LANG=american—america.zhs16cgb231280;export NLS—LANG
2. ora—backup文件对数据库做export导出,导出的文件名可以任意定,本文定为字母“xx”加当天日期,即假如当天日期是12月10号,则导出的文件名为“xx1210.dmp”,以区别于其它日期的备份文件。
ora—backup文件内容:
./oracle/ora—env
#初始化Oracle数据库
rq=′date +″%m%d″ ′
#把当天日期赋予变量rq
rm /backup/
# 清空 /backup目录
exp test/test file=/backup/xx$rq.dmp log=/backup/xx$rq.log
本命令用于在$提示符下,导出test用户的数据(其口令亦为test),,导出文件及日志均放在/backup目录下。

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