关键字：ORA-00824 ORA-00830 statistics_level = basic
今天上午发现测试的服务器重新启动以后oracle就没有起来，手工执行
srvctl start instance -d orcl -i orcl1
出现如下提示：
PRKP-1001 : Error starting instance orcl1 on node xxx-rac1
CRS-0215: Could not start resource 'ora.orcl.orcl1.inst'.
采用这样登陆：
sqlplus "sys as sysdba"
SQL> startup
ORA-00824: cannot set sga_target due to existing internal settings, see alert log for more information
检查alter*.log 文件，并没有发现有什么相关错误。
改用这样启动，成功!
SQL> startup pfile=/u01/app/oracle/admin/orcl/pfile/init.ora
估计spfile文件有问题，再认真检查alert*.log 文件，发现如下：
Tue May 27 09:11:33 2007
ALTER SYSTEM SET statistics_level='BASIC' SCOPE=SPFILE;
可以肯定有人修改spfile文件，将statistics_level='BASIC'修改，再重新启动以后出现问题。问其他人员， 确定是修改过spfile文件。
在/u01/app/oracle/admin/orcl/pfile/spfile.ora,内容如下：
SPFILE='+ASM_DISK1/ORCL/spfileorcl.ora'
STATISTICS_LEVEL=typical
再执行如下操作：
sqlplus "sys as sysdba"
SQL> startup pfile=/u01/app/oracle/admin/orcl/pfile/init.orax
SQL> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string +ASM_DISK1/orcl/spfileorcl.ora
SQL> ALTER SYSTEM SET statistics_level=typical scope=spfile ;
System altered.
关闭数据库，再启动，一切OK！
再重复操作，修改spfile，步骤如下：
SQL> ALTER SYSTEM SET statistics_level='BASIC' SCOPE=both
or
SQL> ALTER SYSTEM SET statistics_level='BASIC' SCOPE=memory
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-00830: cannot set statistics_level to BASIC with auto-tune SGA enabled
ORA-00830: cannot set statistics_level to BASIC with auto-tune SGA enabled
Cause: The user attempted to set statistics_level to BASIC with auto-tune SGA enabled which cannot be done because auto-tune SGA cannot work with statistics_level set to BASIC.
Action: Disable auto-tune SGA and try setting the statistics_level to BASIC again.
也就是说在auto-tune SGA enabled的情况下，是不能修改statistics_level='BASIC'.但是ALTER SYSTEM SET statistics_level='BASIC' SCOPE=SPFILE，却可以正常，导致
下次启动数据库不能正常执行。