今天启动数据库报ORA-03113: end-of-file on communication channel，查看日志：/u01/app/oracle/diag/rdbms/sclerp/sclerp/trace/sclerp_ora_2175.trc，错误如下：
ORA-19815: WARNING: db_recovery_file_dest_size of 4070572032 bytes is 100.00% used, and has 0 remaining bytes available.
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You have following choices to free up space from recovery area:
1. Consider changing RMAN RETENTION POLICY. If you are using Data Guard,
then consider changing RMAN ARCHIVELOG DELETION POLICY.
2. Back up files to tertiary device such as tape using RMAN
BACKUP RECOVERY AREA command.
3. Add disk space and increase db_recovery_file_dest_size parameter to
reflect the new space.
4. Delete unnecessary files using RMAN DELETE command. If an operating
system command was used to delete files, then use RMAN CROSSCHECK and
DELETE EXPIRED commands.
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ORA-19809: limit exceeded for recovery files
ORA-19804: cannot reclaim 43949568 bytes disk space from 4070572032 limit
*** 2013-06-27 14:08:20.102 4132 krsh.c
ARCH: Error 19809 Creating archive log file to '/u01/app/oracle/flash_recovery_area/SCLERP/archivelog/2013_06_27/o1_mf_1_102_%u_.arc'
闪回区没有空间了。
查看回闪空间位置、大小及回闪时间
Sql>show parameter db_recovery '查看回闪位置及回闪区大小
Sql>show parameter flashback '查看回闪位置
Sql>select file_type,PERCENT_SPACE_USED,NUMBER_OF_FILES from v$flash_recovery_area_usage; ‘查看回闪空间文件类型及占用情况
alter system set db_recovery_file_dest_size=8000M;
ALTER SYSTEM SET fast_start_mttr_target = 90 SCOPE=BOTH 实例恢复时间
select GROUP#,bytes/1024/1024||'M',status,archived from v$log;