Oracle Data Guard（RAC+DG)归档删除策略
1、Data Guard 主库归档文件删除策略：
当我们设置：
RMAN>configure archivelog deletion policy to applied on standby;
在Maximum Availability和 Maximum Performance下，RMAN备份归档文件的时候，加上delete input的时候，归档会被删除。
RMAN> configure archivelog deletion policy to none;
此时归档删除策略会被取消。
2、Data Guard 备库归档文件删除策略
此次备库的归档删除策略是在单机版的基础上进行升级，增加了日志功能，支持对2个节点RAC主库的归档文件在备库上删除的功能，可以作为计划任务执行也可以以交互的形式单独执行。
由于备库一般不执行rman备份计划，所以需要脚本删除这些归档日志文件。
[oracle@hainan backup_scripts]$ vim delstarch.sh
export ORACLE_THREAD=$1
export ORACLE_HOME=/u01/app/oracle/product/11.2.0/dbhome_1
export ORACLE_SID=bdspoc
export SHELL_DIR=/u01/app/oracle/backup_scripts
export DATE=$(date +%Y-%m-%d\ %H:%M:%S)
if [ ! $ORACLE_THREAD ];then
read -p "Enter deleted thread[1|2]: "
DB_THREAD=$REPLY
else
DB_THREAD=$ORACLE_THREAD
fi
if [ $DB_THREAD == 1 ];then
del_seq=`ls /arch|grep ^1|cut -f2 -d_|sort -n |head -1`
echo $del_seq "is the minimum archlog sequence"
$ORACLE_HOME/bin/sqlplus -s "sys/***** as sysdba" <<eof >$SHELL_DIR/max_sn.log
set head off;
set feedback;
select max(sequence#) from v\$log_history where THREAD#=1;
exit;
eof
max_sn=`cat /u01/app/oracle/backup_scripts/max_sn.log|awk '{print $1}'|grep ^[0-9]`
#保留最近的20个归档，其他都删除
max_sn=`expr $max_sn - 20`
echo $max_sn "is the maximum archlog sequence"
while [ $del_seq -lt $max_sn ]
do
DATE=$(date +%Y%m%d_%H%M%S)
rm /arch/1_"$del_seq"_816281825.arc
DATE=$(date +%Y-%m-%d\ %H:%M:%S)
#由于log_archive_format 为%t_%s_%r.arc类型，%r为resetlog id
echo "$DATE" /arch/1_"$del_seq"_816281825.arc >> $SHELL_DIR/delarch.log
del_seq=`expr $del_seq + 1`
echo "$DATE" 1_"$del_seq"_816281825.arc
done
elif [ $DB_THREAD == 2 ];then
del_seq=`ls /arch|grep ^2|cut -f2 -d_|sort -n |head -1`
echo $del_seq "is the minimum archlog sequence"
$ORACLE_HOME/bin/sqlplus -s "sys/***** as sysdba" <<eof >$SHELL_DIR/max_sn.log
set head off;
set feedback;
select max(sequence#) from v\$log_history where upper(THREAD#)=2;
exit;
eof
max_sn=`cat /u01/app/oracle/backup_scripts/max_sn.log|awk '{print $1}'|grep ^[0-9]`
max_sn=`expr $max_sn - 20`
echo $max_sn "is the maximum archlog sequence"
while [ $del_seq -lt $max_sn ]
do
rm /arch/2_"$del_seq"_816281825.arc
DATE=$(date +%Y-%m-%d\ %H:%M:%S)
echo "$DATE" /arch/2_"$del_seq"_816281825.arc >> $SHELL_DIR/delarch.log
echo "$DATE" 2_"$del_seq"_816281825.arc has been deleted
del_seq=`expr $del_seq + 1`
done
else
echo "$DATE" There has a fault db_thread value! >> $SHELL_DIR/delarch.log
fi
可以交互式执行，例如：
[oracle@hainan backup_scripts]$ sh delstarch.sh
Enter deleted thread[1|2]: 1 --选择删除从哪个节点归档来的日志文件
也可以做成计划任务执行该脚本
[root@hainan ~]# crontab -l
0 1 * * * su - oracle -c /u01/app/oracle/backup_scripts/delstarch.sh 1
0 2 * * * su - oracle -c /u01/app/oracle/backup_scripts/delstarch.sh 2
每天1点执行1节点归档来的日志文件，2点执行2节点归档来的日志文件。
