1. 当启动oracle 发现报错
SQL> startup
报错：
ORA-03113: end-of-file on communication channel
查看alert.log文件，发现
ORA-03113: end-of-file on communication channel
cannot reclaim 45680128 bytes disk space from 2147483648 limit
ARCH: Error 19809 Creating archive log file to '/u01/flash_recovery_area/ORCL/archivelog/2014_01_17/o1_mf_1_6_%u_.arc'
这是由于归档表空间已满，分配不到空间所致
解决办法如下：打开数据库至mount模式，而后删除需要废弃的文件：
RMAN> startup nomount;
Oracle instance started
Total System Global Area 835104768 bytes
Fixed Size 2217952 bytes
Variable Size 587204640 bytes
Database Buffers 243269632 bytes
Redo Buffers 2412544 bytes
RMAN> resotre spfile from autobackup;
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01009: syntax error: found "identifier": expecting one of: "advise, allocate, alter, backup, @, catalog, change, configure, connect, convert, copy, create, crosscheck, delete, drop, duplicate, exit, flashback, grant, host, import, list, mount, open, print, quit, recover, register, release, repair, replace, report, reset, restore, resync, revoke, run, send, set, show, shutdown, spool, sql, startup, switch, transport, unregister, upgrade, validate, {, "
RMAN-01008: the bad identifier was: resotre
RMAN-01007: at line 1 column 1 file: standard input
RMAN> alter database mount;
database mounted
RMAN> delete obsolete;
RMAN retention policy will be applied to the command
RMAN retention policy is set to recovery window of 1 days
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=19 device type=DISK
Deleting the following obsolete backups and copies:
Type Key Completion Time Filename/Handle
-------------------- ------ ------------------ --------------------
Backup Set 2 27-DEC-13
Backup Piece 2 27-DEC-13 /u01/flash_recovery_area/ORCL/backupset/2013_12_27/o1_mf_nnndf_TAG20131227T172528_9cwb48k0_.bkp
Archive Log 2 27-DEC-13 /u01/flash_recovery_area/ORCL/archivelog/2013_12_27/o1_mf_1_7_9cwq8sbj_.arc
Backup Set 1 27-DEC-13
Backup Piece 1 27-DEC-13 /u01/flash_recovery_area/ORCL/backupset/2013_12_27/o1_mf_ncsnf_TAG20131227T172528_9cwb7lrp_.bkp
Archive Log 1 27-DEC-13 /u01/flash_recovery_area/ORCL/archivelog/2013_12_27/o1_mf_1_6_9cwq0xm1_.arc
Archive Log 3 27-DEC-13 /u01/flash_recovery_area/ORCL/archivelog/2013_12_27/o1_mf_1_5_9cwm7cv6_.arc
Do you really want to delete the above objects (enter YES or NO)? yes
deleted backup piece
backup piece handle=/u01/flash_recovery_area/ORCL/backupset/2013_12_27/o1_mf_nnndf_TAG20131227T172528_9cwb48k0_.bkp RECID=2 STAMP=835306248
deleted archived log
archived log file name=/u01/flash_recovery_area/ORCL/archivelog/2013_12_27/o1_mf_1_7_9cwq8sbj_.arc RECID=2 STAMP=835306247
deleted backup piece
backup piece handle=/u01/flash_recovery_area/ORCL/backupset/2013_12_27/o1_mf_ncsnf_TAG20131227T172528_9cwb7lrp_.bkp RECID=1 STAMP=835306248
deleted archived log
archived log file name=/u01/flash_recovery_area/ORCL/archivelog/2013_12_27/o1_mf_1_6_9cwq0xm1_.arc RECID=1 STAMP=835306247
deleted archived log
archived log file name=/u01/flash_recovery_area/ORCL/archivelog/2013_12_27/o1_mf_1_5_9cwm7cv6_.arc RECID=3 STAMP=835306247
Deleted 5 objects
RMAN> alter datatbase open;
ORA-03113: end-of-file on communication channel
