export ORACLE_BASE=/opt/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11gR2/db
export GRID_HOME=/opt/oracrs/product/11gR2/grid
export ORACLE_TERM=xterm
export NLS_LANG=AMERICAN_AMERICA.AL32UTF8
export ORACLE_SID=iptvsqm
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib:$ORACLE_HOME/rdbms/lib
rman target / nocatalog log /opt/oracle/db/oradata/iptvsqm_archlog/delete_archive.log append<<EOF
allocate channel for maintenance type disk;
crosscheck archivelog all;
delete expired archivelog all;
delete noprompt archivelog all completed before 'sysdate-3';
EOF
前面这些环境变量可以不需要设置，但是前提是这台主机上只有一个数据库实例，有多个实例就要设置环境变量了。
corntab脚本
root用户：crontab -e
* * * * * su - oracle -c /ora_arch/clear_arch.sh >>/archive/delete_arch.log &