【案例】 在重启数据库过程中;
              |           SQL> startup             ORACLE instance started.           Total System Global Area 1.0489E+10 bytes             Fixed Size                  2216224 bytes              Variable Size            1677725408 bytes              Database Buffers         8791261184 bytes              Redo Buffers               17842176 bytes              Database mounted.              ORA-03113: end-of-file on communication channel              Process ID: 29821              Session ID: 24 Serial number: 3         |      
   
  oracle启动报错;具体原因还须查看告警日志
     
*** 2015-09-21 15:30:40.856     
*** SESSION ID:(24.3) 2015-09-21 15:30:40.856     
*** CLIENT ID:() 2015-09-21 15:30:40.856     
*** SERVICE NAME:() 2015-09-21 15:30:40.856     
*** MODULE NAME:(sqlplus@szmlserver95_205.easou.com (TNS V1-V3)) 2015-09-21 15:30:40.856     
*** ACTION NAME:() 2015-09-21 15:30:40.856     
  
DDE rules only execution for: ORA 312     
----- START Event Driven Actions Dump ----     
---- END Event Driven Actions Dump ----     
----- START DDE Actions Dump -----     
Executing SYNC actions     
----- START DDE Action: 'DB_STRUCTURE_INTEGRITY_CHECK' (Async) -----     
Successfully dispatched     
----- END DDE Action: 'DB_STRUCTURE_INTEGRITY_CHECK' (SUCCESS, 0 csec) -----     
Executing ASYNC actions     
----- END DDE Actions Dump (total 0 csec) -----     
DDE: Problem Key 'ORA 312' was flood controlled (0x1) (no incident)     
ORA-00312: online log 1 thread 1: '+HZ_DG1/hz/onlinelog/group_1.261.787682297'     
ORA-00312: online log 1 thread 1: '+HZ_DG1/hz_dg1/onlinelog/group_1.273.788525363'     
ORA-16014: log 1 sequence# 18130 not archived, no available destinations     
ORA-00312: online log 1 thread 1: '+HZ_DG1/hz/onlinelog/group_1.261.787682297'     
ORA-00312: online log 1 thread 1: '+HZ_DG1/hz_dg1/onlinelog/group_1.273.788525363'
              |                       *** 2015-09-21 15:30:40.856              *** SESSION ID:(24.3) 2015-09-21 15:30:40.856              *** CLIENT ID:() 2015-09-21 15:30:40.856              *** SERVICE NAME:() 2015-09-21 15:30:40.856              *** MODULE NAME:(sqlplus@szmlserver95_205.easou.com (TNS V1-V3)) 2015-09-21 15:30:40.856              *** ACTION NAME:() 2015-09-21 15:30:40.856                 DDE rules only execution for: ORA 312              ----- START Event Driven Actions Dump ----              ---- END Event Driven Actions Dump ----              ----- START DDE Actions Dump -----              Executing SYNC actions              ----- START DDE Action: 'DB_STRUCTURE_INTEGRITY_CHECK' (Async) -----              Successfully dispatched              ----- END DDE Action: 'DB_STRUCTURE_INTEGRITY_CHECK' (SUCCESS, 0 csec) -----              Executing ASYNC actions              ----- END DDE Actions Dump (total 0 csec) -----              DDE: Problem Key 'ORA 312' was flood controlled (0x1) (no incident)              ORA-00312: online log 1 thread 1: '+HZ_DG1/hz/onlinelog/group_1.261.787682297'              ORA-00312: online log 1 thread 1: '+HZ_DG1/hz_dg1/onlinelog/group_1.273.788525363'              ORA-16014: log 1 sequence# 18130 not archived, no available destinations              ORA-00312: online log 1 thread 1: '+HZ_DG1/hz/onlinelog/group_1.261.787682297'              ORA-00312: online log 1 thread 1: '+HZ_DG1/hz_dg1/onlinelog/group_1.273.788525363'         |      
   
  发现日志组1存在问题;到网上查看资料
              |           SQL> shutdown immediate;             ORA-01034: ORACLE not available              ORA-27101: shared memory realm does not exist              Linux-x86_64 Error: 2: No such file or directory              SQL> startup mount              ORACLE instance started.           Total System Global Area 1.0489E+10 bytes             Fixed Size                  2216224 bytes              Variable Size            1677725408 bytes              Database Buffers         8791261184 bytes              Redo Buffers               17842176 bytes              Database mounted.              SQL> alter database clear unarchived logfile group 1;           Database altered.           SQL> shutdown immediate;             ORA-01109: database not open                       Database dismounted.              ORACLE instance shut down.              SQL> startup              ORACLE instance started.           Total System Global Area 1.0489E+10 bytes             Fixed Size                  2216224 bytes              Variable Size            1677725408 bytes              Database Buffers         8791261184 bytes              Redo Buffers               17842176 bytes              Database mounted.              Database opened.              SQL> exit         |