从源库10gR2导出（EXP/IMP）数据到目标库11gR2（开启了连接池）时的错误及解决方法，见下：

--第一次导入：

[oracle@db1 20131226]$ imp 用户/密码@width   file=iflashbuy.dmp  fromuser=iflashbuy  touser=iflashbuytest  IGNORE=Y


Import: Release 11.2.0.1.0 - Production on Fri Dec 27 14:46:47 2013

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

IMP-00003: ORACLE error 56605 encountered

ORA-56605: DRCP: Session switching and migration not allowed

IMP-00000: Import terminated unsuccessfully


查看oracle文档说是连接池不支持，需要关闭。

ORA-56605: DRCP: Session switching and migration not allowed

Cause: Application tried to switch or migrate session across connections.

Action: This usage is irrelevant in the Database Resident connection pooling context and is not supported. Release existing session.


--关闭连接池：

SQL> execute dbms_connection_pool.stop_pool;

PL/SQL procedure successfully completed


--再次导入报listener的错误，重启listener后导入还是报同样的错误：

[oracle@db1 20131226]$  imp 用户/密码@width  file=iflashbuy.dmp  fromuser=iflashbuy  touser=iflashbuytest  IGNORE=Y


Import: Release 11.2.0.1.0 - Production on Fri Dec 27 14:54:06 2013

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

IMP-00058: ORACLE error 12520 encountered

ORA-12520: TNS:listener could not find available handler for requested type of server

IMP-00000: Import terminated unsuccessfully


--最后尝试不加oracle_sid，导入成功，见下：

[oracle@db1 20131226]$ imp 用户/密码   file=iflashbuy.dmp  fromuser=iflashbuy  touser=iflashbuytest  IGNORE=Y


Import: Release 11.2.0.1.0 - Production on Fri Dec 27 14:58:27 2013

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

Export file created by EXPORT:V10.02.01 via direct path

Warning: the objects were exported by IFLASHBUY, not by you

import done in ZHS16GBK character set and AL16UTF16 NCHAR character set

. . importing table                         "AREA"          8 rows imported

....................

. . importing table                   "T_TMP_AREA"       2913 rows imported

. . importing table               "T_TMP_SOFTWARE"         25 rows imported

Import terminated successfully without warnings.


  为什么有这样的限制不太清楚，10g向10g、11g向11g导数据是不会有这样的限制。