一、问题提出：
在一台数据库主机上做exp，一样的语句，用exp导出，加上direct=y参数就报错：
oracle@gd_rdb01:/rpt_bak$exp report/pwd@gdreport tables=hjm_jfbb_close direct=y log=111.log Export: Release9.2.0.6.0 - Production on Tue Jan 16 11:31:07 2007 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Connected to: Oracle9i Enterprise Edition Release 9.2.0.6.0 - 64bit Production With the Partitioning, OLAP and Oracle Data Mining options JServer Release 9.2.0.6.0 - Production Export done in ZHS16GBK character set and UTF8 NCHAR character set About to export specified tables via Direct Path ... EXP-00056: ORACLE error 942 encountered ORA-00942: table or view does not exist EXP-00000: Export terminated unsuccessfully
但是这个表是存在的，如果不加direct的参数可以正常导出：
oracle@gd_rdb01:/rpt_bak$exp report/pwd@gdreport tables=hjm_jfbb_close log=222.log Export: Release9.2.0.6.0 - Production on Tue Jan 16 11:31:37 2007 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Connected to: Oracle9i Enterprise Edition Release 9.2.0.6.0 - 64bit Production With the Partitioning, OLAP and Oracle Data Mining options JServer Release 9.2.0.6.0 - Production Export done in ZHS16GBK character set and UTF8 NCHAR character set About to export specified tables via Conventional Path ... . . exporting table HJM_JFBB_CLOSE 70 rows exported Export terminated successfully without warnings. oracle@gd_rdb01:/rpt_bak$
以下是数据库的相关信息：
数据库版本：
SQL> select * from v$version; BANNER ---------------------------------------------------------------- Oracle9i Enterprise Edition Release9.2.0.6.0- 64bit Production PL/SQL Release 9.2.0.6.0 - Production CORE 9.2.0.6.0 Production TNS for HPUX: Version 9.2.0.6.0 - Production NLSRTL Version 9.2.0.6.0 - Production 环境变量： SQL> SELECT NAME,VALUE FROM v$parameter 2 WHERE NAME LIKE '%nls_language%'; NAME VALUE -------------------- -------------------- nls_language AMERICAN SQL> 系统环境变量： oracle@gd_rdb01:/rpt_bak$ env _=/usr/bin/env MANPATH=/usr/share/man/%L:/usr/share/man:/usr/contrib/man/%L:/usr/contrib/man:/usr/local/man/%L:/usr/local/man:/opt/upgrade/share/man/%L:/opt/upgrade/share/man:/opt/pd/share/man/%L:/opt/pd/share/man:/opt/pd/share/man/%L:/opt/pd/share/man:/opt/pd/share/man/%L:/opt/pd/share/man:/opt/ignite/share/man/%L:/opt/ignite/share/man:/opt/mx/share/man:/opt/resmon/share/man:/usr/dt/share/man:/opt/samba/man:/opt/gnome/man:/opt/perf/man/%L:/opt/perf/man:/opt/perl/man:/opt/wbem/share/man:/opt/openssl/man:/opt/openssl/prngd/man:/opt/hparray/share/man/%L:/opt/hparray/share/man:/opt/graphics/common/man:/opt/EMCpower/share:/opt/omni/lib/man:/opt/ssh/share/man SHLIB_PATH=/oracle/app/oracle/product/920/lib32:/oracle/app/oracle/product/920/rdbms/lib32 PATH=/oracle/app/oracle/product/920/bin:/usr/sbin:/usr/ccs/bin:/opt/perl5/bin:/usr/bin:/usr/ccs/bin:/usr/contrib/bin:/opt/hparray/bin:/opt/nettladm/bin:/opt/upgrade/bin:/opt/fcms/bin:/opt/pd/bin:/usr/bin/X11:/usr/contrib/bin/X11:/opt/resmon/bin:/opt/mx/bin:/opt/gnome/bin:/opt/perf/bin:/opt/mozilla:/opt/perl/bin:/opt/wbem/bin:/opt/wbem/sbin:/usr/sbin/diag/contrib:/opt/graphics/common/bin:/opt/ignite/bin:/opt/omni/bin:/opt/ssh/bin:.:/oracle/OPatch:. NLS_LANG=AMERICAN_AMERICA.ZHS16GBK COLUMNS=132 ORACLE_BASE=/oracle/app/oracle EDITOR=vi LOGNAME=oracle ERASE=^H ORACLE_SID=gdreport PS1=oracle@gd_rdb01:$PWD$ SHELL=/usr/bin/sh TNS_ADM=/oracle/app/oracle/product/920/network/admin ORA_NLS33=/oracle/app/oracle/product/920/ocommon/nls/admin/data HOME=/home/oracle TERM=vt100 LD_LIBRARY_PATH=/oracle/app/oracle/product/920/lib:/lib:/usr/lib:/oracle/app/oracle/product/920/rdbms/lib ORACLE_HOME=/oracle/app/oracle/product/920 PWD=/rpt_bak TZ=EAT-8 LINES=49
二、问题分析：
下面用errorstack event来定位问题
alter session set events ‘942 trace name errorstack level 1’;
exp report/pwd@gdreport tables=hjm_jfbb_close log=222.log
同时另看窗口观察alertlog
OS Pid: 10948 executed alter session set events '942 trace name errorstack level 1' Wed Jan 17 09:44:17 2007 Errors in file /oracle/app/oracle/admin/gdreport/udump/gdreport_ora_11024.trc: ORA-00942: table or view does not exist Wed Jan 17 09:46:17 2007 OS Pid: 10948 executed alter session set events '942 trace name errorstack off'
alter session set events ‘942 trace name errorstack off’;
查看trace文件：
/oracle/app/oracle/admin/gdreport/udump/gdreport_ora_11024.trc
Oracle9i Enterprise Edition Release9.2.0.6.0 – 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release9.2.0.6.0 – Production
ORACLE_HOME = /oracle/app/oracle/product/920
System name:HP-UX
Node name: gd_rdb01
Release: B.11.11
Version: U
Machine:9000/800
Instance name: gdreport
Redo thread mounted by this instance: 1
Oracle process number: 11
Unix process pid: 11024, image: oracle@gd_rdb01 (TNS V1-V3)
*** SESSION ID:(100.42947) 2007-01-17 09:44:17.397
*** 2007-01-17 09:44:17.397
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
—– Call Stack Trace —–
calling call entry argument values in hex
location type point (? means dubious value)
——————– ——– ——————– —————————-
ksedmp()+184 ? ksedst() 800003FFBFFFC250 ?
800000010000C18C?
800000010000C18C?
81BC2D681E93E ?
ksddoa()+304 ? ksedmp() 000000000 ? 000000000 ?
……
从trace文件上看可能是SYS.EXPCOMPRESSEDTAB这个表发生了问题，登陆sqlplus查询，发现该视图不存在：
SQL> select * from EXPCOMPRESSEDTAB;
select * from EXPCOMPRESSEDTAB
*
ERROR at line 1:
ORA-00942: table or view does not exist
三、问题解决：
找到$ORACLE_HOME/rdbms/admin/catexp.sql，查找其中关于EXPCOMPRESSEDTAB的语句，并且执行：
CREATE OR REPLACE VIEW sys.expcompressedtab
(SPARE1, TOBJ$) 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;
SQL> host
oracle@gd_rdb01:/oracle/app/oracle/admin/gdreport/bdump$ hjm_jfbb_close file=kkk.dmp log=nnn.log direct=y <
Export: Release9.2.0.6.0 - Production on Wed Jan 17 12:06:00 2007
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
Connected to: Oracle9i Enterprise Edition Release 9.2.0.6.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.6.0 - Production
Export done in ZHS16GBK character set and UTF8 NCHAR character set
About to export specified tables via Direct Path ...
. . exporting table HJM_JFBB_CLOSE 70 rows exported
Export terminated successfully without warnings.
=====================================================================
四、alter system set events相关知识：
格式：alter system|session set events '[eventnumber|immediate] trace name eventname [forever] [, level levelnumber] : .......'
通过:符号，可以连续设置多个事件，也可以通过连续使用alter session set events来设置多个事件。
格式说明：eventnumber指触发dump的事件号，事件号可以是Oracle错误号（出现相应错误时跟踪指定的事件）或oralce内部事件号，内部事件号在10000到10999之间，不能与immediate关键字同用。
immediate关键字表示命令发出后，立即将指定的结构dump到跟踪文件中，这个关键字只用在alter session语句中，并且不能与eventnumber、forever关键字同用。
trace name是关键字。
eventname指事件名称（见后面），即要进行dump的实际结构名。若eventname为context，则指根据内部事件号进行跟踪。
forever关键字表示事件在实例或会话的周期内保持有效状态，不能与immediate同用。
level为事件级别关键字。但在dump错误栈(errorstack)时不存在级别。
levelnumber表示事件级别号，一般从1到10，1表示只dump结构头部信息，10表示dump结构的所有信息。
1、buffers事件：dump SGA缓冲区中的db buffer结构
alter session set events 'immediate trace name buffers level 1'; --表示dump缓冲区的头部。
2、blockdump事件：dump数据文件、索引文件、回滚段文件结构
alter session set events 'immediate trace name blockdump level 66666'; --表示dump块地址为6666的数据块。
在Oracle 8以后该命令已改为：
alter system dump datafile 11 block 9; --表示dump数据文件号为11中的第9个数据块。
3、controlf事件：dump控制文件结构
alter session set events 'immediate trace name controlf level 10'; --表示dump控制文件的所有内容。
4、locks事件：dump LCK进程的锁信息
alter session set events 'immediate trace name locks level 5';
5、redohdr事件：dump redo日志的头部信息
alter session set events 'immediate trace name redohdr level 1'; --表示dump redo日志头部的控制文件项。
alter session set events 'immediate trace name redohdr level 2'; --表示dump redo日志的通用文件头。
alter session set events 'immediate trace name redohdr level 10'; --表示dump redo日志的完整文件头。
注意：redo日志的内容dump可以采用下面的语句:
alter system dump logfile 'logfilename';
6、loghist事件：dump控制文件中的日志历史项
alter session set events 'immediate trace name loghist level 1'; --表示只dump最早和最迟的日志历史项。
levelnumber大于等于2时，表示2的levelnumber次方个日志历史项。
alter session set events 'immediate trace name loghist level 4'; --表示dump 16个日志历史项。
7、file_hdrs事件：dump所有数据文件的头部信息
alter session set events 'immediate trace name file_hdrs level 1'; --表示dump所有数据文件头部的控制文件项。
alter session set events 'immediate trace name file_hdrs level 2'; --表示dump所有数据文件的通用文件头。
alter session set events 'immediate trace name file_hdrs level 10'; --表示dump所有数据文件的完整文件头。
8、errorstack事件：dump错误栈信息，通常Oracle发生错误时前台进程将得到一条错误信息，但某些情况下得不到错误信息，可以采用这种方式得到Oracle错误。
alter session set events '604 trace name errorstack forever'; --表示当出现604错误时，dump错误栈和进程栈。
9、systemstate事件：dump所有系统状态和进程状态
alter session set events 'immediate trace name systemstate level 10'; --表示dump所有系统状态和进程状态。
10、coalesec事件：dump指定表空间中的自由区间
levelnumber以十六进制表示时，两个高位字节表示自由区间数目，两个低位字节表示表空间号，如0x00050000表示dump系统表空间中的5个自由区间，转换成十进制就是327680，即：
alter session set events 'immediate trace name coalesec level 327680';
11、processsate事件：dump进程状态
alter session set events 'immediate trace name processsate level 10';
12、library_cache事件：dump library cache信息
alter session set events 'immediate trace name library_cache level 10';
13、heapdump事件：dump PGA、SGA、UGA中的信息
alter session set events 'immediate trace name heapdump level 1';
14、row_cache事件：dump数据字典缓冲区中的信息
alter session set events 'immediate trace name row_cache level 1';