今天用EXP命令導Oracle數據庫，出現如下錯誤信息：
[oracle@yingxiang-testServer1 ~]$ exp imgpf/imgpf@orcl file=/prlife/db/USDMP20140428.dmp
Export: Release 11.2.0.4.0 - Production on Mon Apr 28 09:53:47 2014
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
EXP-00056: ORACLE error 12154 encountered
ORA-12154: TNS:could not resolve the connect identifier specified
EXP-00000: Export terminated unsuccessfully
查看$ORACLE_HOME/network/admin下的 tnsnames.ora 文件，如下所示：
ORCL_YZJ =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 10.132.2.147)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = orcl)
)
)
於是，執行導出表命令如下，導出成功：
[oracle@yingxiang-testServer1 ~]$ exp imgpf/imgpf@ORCL_YZJ file=/home/oracle/table_space/USDMP20140428.dmp
Export: Release 11.2.0.4.0 - Production on Mon Apr 28 14:54:58 2014
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Export done in UTF8 character set and UTF8 NCHAR character set
server uses AL32UTF8 character set (possible charset conversion)
About to export specified users ...
. exporting pre-schema procedural objects and actions