版本不当导致的exp出错

在一次导出操作时遇到了ORA-00904,ORA-01003错误，多方搜索也几无所得。

导出的大概情形如下：

D:\>expfile=d:\xx.dmp

Export: Release 10.2.0.4.0 - Production on Fri Oct 24 13:25:33 

Copyright (c) 1982, 2007, .  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options
Export done in ZHS16GBK character set and AL16UTF16 NCHAR character set
. exporting pre-schema procedural objects and actions
. exporting foreign function library names for user USER
. exporting PUBLIC type synonyms
. exporting private type synonyms
. exporting object type definitions for user USER
About to export USER's objects ...
. exporting database links
. exporting sequence numbers
. exporting cluster definitions
. about to export USER's tables via Conventional Path ...
. . exporting table                          LC_BL          0 rows exported
. . exporting table                        LC_BLLX          0 rows exported
. . exporting table                         LC_DLR          0 rows exported
. . exporting table                          LC_MB          0 rows exported
. . exporting table                        LC_MBJD          0 rows exported
. . exporting table                        LC_MBLB          0 rows exported
. . exporting table                        LC_RYXZ          0 rows exported
. . exporting table                        LC_SJJD          0 rows exported
. . exporting table                        LC_SJLC          0 rows exported
. . exporting table                        LC_SWLB          4 rows exported
. . exporting table                   OA_BBS_ANNEX          0 rows exported
. . exporting table                   OA_BBS_BOARD          0 rows exported
. . exporting table                  OA_BBS_DETAIL
EXP-00008: ORACLE error 904 encountered
ORA-00904: "IFREEPOOL": invalid identifier
. . exporting table                     OA_CL_CLSY
EXP-00008: ORACLE error 1003 encountered
ORA-01003: no statement parsed
. . exporting table                     OA_CL_JBXX
EXP-00008: ORACLE error 904 encountered
ORA-00904: "IFREEPOOL": invalid identifier
. . exporting table                       OA_CL_WX
EXP-00008: ORACLE error 1003 encountered
ORA-01003: no statement parsed
. . exporting table                        OA_CYDH          0 rows exported
. . exporting table                        OA_CYHB          0 rows exported
.............................
.............................
. exporting synonyms
. exporting views
. exporting stored procedures
. exporting operators
EXP-00008: ORACLE error 904 encountered
ORA-00904: "OLEVEL": invalid identifier
EXP-00000: Export terminated unsuccessfully

服务器和客户端两边连接都很正常，百思不得解，难道是导出版本的问题？不至于啊，1024导出1023的库，之前操作过，没发现过这个问题，而且看提示不像啊，众所周知版本错误会提示ORA-06550。实在无法，最后报着死马当活马医的想法尝试换了一个同版本的客户端执行exp，结果顺利执行。

后来又经过多番尝试，发现出错的均是含lob字段的表，看来一方面oracle在执行exp时对版本的处理非常严格，即使大版本相同，小版本有略微差异也会导致exp时报错，另一方面是处理规则也存在版本延续的情况，如果不涉及到处理规则的变化，即使exp时客户端版本与服务器不符，导出时也有可能不报错(运气好的话)。

将此次事件记录下来以加强记忆，以后执行导出还是都尽可能确保版本一致吧(起码exp的客户端版本不能高于服务器)。