用errorstack event來定位exp導出時direct=y參數報錯的問題
1.exp導出時加上direct=y參數出錯，顯示ora-00942錯誤顯示表格不存在，經檢查表格是存在的。
EXP-00056:
ORA-00942:
SQL> conn amy/amy@test129
已連線.
SQL> select count(*) from class_info;
COUNT(*)
----------
6
2.用errorstack event來定位問題
打開errorstack
SQL>alter system set events '942 trace name errorstack level 1';
再執行報錯的exp
關閉errorstack
SQL>alter system set events'942 trace name errorstack off';
3．查看警告日志文件
[oracle@MESTEST bdump]$ tail -n 10 alert_mes.log
Sat Nov 20 15:37:22 2010
OS Pid: 13391 executed alter system set events '942 trace name errorstack level 1'
Sat Nov 20 15:37:28 2010
Errors in file /opt/oracle/admin/mes/udump/mes_ora_13403.trc:
ORA-00942: table or view does not exist
OS Pid: 13405 executed alter system set events '942 trace name errorstack off'
4.檢查警告日志中出現的trace文件，發現是有系統表SYS.EXPCOMPRESSEDTAB不存在導致的，
[oracle@MESTEST bdump]$ more /opt/oracle/admin/mes/udump/mes_ora_13403.trc
*** SESSION ID:(74.48444) 2010-11-20 15:37:27.982
*** 2010-11-20 15:37:27.982
ksedmp: internal or fatal error
ORA-00942: table or view does not exist
Current SQL statement for this session:
SELECT COUNT(*) FROM SYS.EXPCOMPRESSEDTAB WHERE TOBJ$ = :1
5.查找/opt/oracle/9205/rdbms/admin /catexp.sql腳本中關於SYS.EXPCOMPRESSEDTAB的腳本並執行。
REM
REM View to see if a table is compressed (new for 10i).
REM
CREATE OR REPLACE VIEW sys.expcompressedtab
(SPARE1, TOBJ$) AS
SELECT s.spare1, t.obj#
FROM sys.tab$ t, sys.seg$ s
WHERE t.ts# = s.ts#
AND t.file# = s.file#
AND t.block# = s.block#
AND s.type# = 5
AND (bitand(s.spare1,4096) = 4096 OR bitand(s.spare1,2048) = 2048)
/
GRANT SELECT ON sys.expcompressedtab TO PUBLIC;
6.再執行帶direct=y的導出，錯誤消失了，可以正常導出。
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