自己利用crontab设置定期清理数据库归档日志的任务，脚本执行不起作用，能否帮忙给看看

#!/usr/bin/ksh

DATETIME=`date +"%d-%m-%Y"`

su - oracle -c "touch /arch1/del_arch.log"

echo "-----------------------------Start Time-----------------------------" >> /arch1/del_arch.log;

date >> /arch1/del_arch.log 

echo "--------------------------------------------------------------------" >> /arch1/del_arch.log;

su - oracle -c "rman target /  msglog '/arch1/del_arch.log' append"  <<EOF

run{

sql 'alter system switch logfile';

crosscheck archivelog all;

delete noprompt archivelog all completed before 'sysdate-1';

#delete noprompt archivelog until time "to_date('2018-06-05 08:00:00','yyyy-mm-dd hh24:mi:ss')";

}

EOF

echo "------------------------------End Time------------------------------" >> /arch1/del_arch.log;

date >> /arch1/del_arch.log

echo "--------------------------------------------------------------------" >> /arch1/del_arch.log;

mv /arch1/del_arch.log /arch1/del_arch_$DATETIME.log