客户数据库遭受存储损坏无法打开，数据文件存在大量坏块，我们强制打开数据库后遇到了如下错误：
Tue Feb 22 17:22:59 2011
Errors in file d:\programfiles\oracle\admin\agzt\bdump\agzt_smon_7512.trc:
ORA-00600: internal error code, arguments: [25012], [0], [16], [], [], [], [], []
Tue Feb 22 17:28:13 2011
Non-fatal internal error happenned while SMON was doing IOT PMO transient table cleanup.
SMON encountered 1 out of maximum 100 non-fatal internal errors.
Tue Feb 22 17:28:13 2011
Errors in file d:\programfiles\oracle\admin\agzt\bdump\agzt_smon_7512.trc:
ORA-00600: internal error code, arguments: [25012], [0], [16], [], [], [], [], []
Non-fatal internal error happenned while SMON was doing IOT PMO transient table cleanup.
SMON encountered 2 out of maximum 100 non-fatal internal errors.
Tue Feb 22 17:32:06 2011
Errors in file d:\programfiles\oracle\admin\agzt\udump\agzt_ora_8040.trc:
这里Oracle提示，SMON遇到了内部错误，最大允许100次，不断计数增长。
基于对Oracle的信任，我想一定是有一个内部参数用于控制这个次数，于是就查询一下内部视图：
SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ
FROM SYS.x$ksppi x, SYS.x$ksppcv y
WHERE x.indx = y.indx AND x.ksppinm LIKE '%&par%'
/
Enter value for par: smon
old 3: WHERE x.indx = y.indx AND x.ksppinm LIKE '%&par%'
new 3: WHERE x.indx = y.indx AND x.ksppinm LIKE '%smon%'
NAME VALUE DESCRIB
------------------------------ -------- -----------------------------------------------
_smon_internal_errlimit 100 limit of SMON internal errors
_smon_undo_seg_rescan_limit 10 limit of SMON continous undo segments re-scan
可以将_smon_internal_errlimit这个值调高，这样就可以保证数据库能在较多非致命错误下，不要崩溃。
这个参数在这个Case里对我有效，记录于此。