oerr可以在Linux和UNIX操作系统上查询简短的报错信息的含义，可以很好的辅助排查Oracle故障。

1.oerr的使用方法
[oracle@BJS ~]$ oerr ora 12571
12571, 00000, "TNS:packet writer failure"
// *Cause: An error occurred during adatasend.
// *Action: Not normally visible to the user. For further details, turn
// on tracing and reexecute the operation. If error persists, contact
// Oracle Customer Support.

2.使用which命令查询oerr工具的位置
secooler@testdb /home/oracle$ which oerr
/u01/app/oracle/product/10.2/db10g/bin/oerr

3.看一下这个脚本文件记录的内容
secooler@testdb /home/oracle$ vi /u01/app/oracle/product/10.2/db10g/bin/oerr

脚本中 82 Msg_File=$ORACLE_HOME/$Component/mesg/${Facility}us.msg
这里似乎暗示着我们，所有的检索信息都是来自于这些*.msg文件

4.在ORACLE_HOME目录中使用find命令查找msg文件

[oracle@NcDbEmulator mesg]$ find $ORACLE_HOME -name mesg

/oracle/app/oracle/dbhome/network/mesg

/oracle/app/oracle/dbhome/has/mesg

/oracle/app/oracle/dbhome/usm/mesg

/oracle/app/oracle/dbhome/nls/mesg

/oracle/app/oracle/dbhome/racg/mesg

/oracle/app/oracle/dbhome/css/mesg

/oracle/app/oracle/dbhome/srvm/mesg

/oracle/app/oracle/dbhome/olap/mesg

/oracle/app/oracle/dbhome/oracore/mesg

/oracle/app/oracle/dbhome/plsql/mesg

/oracle/app/oracle/dbhome/ldap/mesg

/oracle/app/oracle/dbhome/sqlplus/mesg

/oracle/app/oracle/dbhome/ord/mesg

/oracle/app/oracle/dbhome/crs/mesg

/oracle/app/oracle/dbhome/odbc/mesg

/oracle/app/oracle/dbhome/xdk/mesg

/oracle/app/oracle/dbhome/mesg

/oracle/app/oracle/dbhome/precomp/mesg

/oracle/app/oracle/dbhome/slax/mesg

/oracle/app/oracle/dbhome/csmig/mesg

/oracle/app/oracle/dbhome/ctx/mesg

/oracle/app/oracle/dbhome/rdbms/mesg

/oracle/app/oracle/dbhome/opmn/mesg

[oracle@NcDbEmulator mesg]$ cd /oracle/app/oracle/dbhome/rdbms/mesg/

[oracle@NcDbEmulator mesg]$ ls *.msg

amduus.msg    dgmus.msg  gimus.msg   kfodus.msg  kopus.msg  nidus.msg  oraus.msg   sbtus.msg  udius.msg

asmcmdus.msg  diaus.msg  impus.msg   kfsgus.msg  kupus.msg  ocius.msg  qsmus.msg   smgus.msg  ulus.msg

dbvus.msg     expus.msg  kfedus.msg  kgpus.msg   lcdus.msg  opwus.msg  rmanus.msg  udeus.msg

.msb格式的文件是二进制文件。

从以上msg格式的文件，可以看出oerr可以查询的错误信息类型。例如：

oraus.msg 对应ORA错误，

$ oerr lrm 112

112, 0, "multiple values not allowed for parameter '%.*s'"

// *Cause: An attempt was made to specify multiple values for a parameter which

//         can take only one value.

// *Action: Do not specify more than one value for this parameter.

这是在使用expdp时使用directory参数不当时可能会产生的错误。

$ oerr exp 91

00091, 00000, "Exporting questionable statistics."

// *Cause:  Export was able export statistics, but the statistics may not be

//          usuable. The statistics are questionable because one or more of

//          the following happened during export: a row error occurred, client

//          character set or NCHARSET does not match with the server, a query

//          clause was specified on export, only certain partitions or

//          subpartitions were exported, or a fatal error occurred while

//          processing a table.

// *Action: To export non-questionable statistics, change the client character

//          set or NCHARSET to match the server, export with no query clause,

//          export complete tables. If desired, import parameters can be

//          supplied so that only non-questionable statistics will be imported,

//          and all questionable statistics will be recalculated.

$ oerr imp 17

00017, 00000, "following statement failed with ORACLE error %lu:"

// *Cause:  Import failed to execute the statement from the export file 

//          because of an Oracle error. 

// *Action: Look up the accompanying Oracle message in the ORA message 

//          chapters of this manual and take appropriate action. 

这是在使用EXP和IMP时可能产生的错误

OERR能检索的错误还有很多，包括CLSR、OCI、TNS、UDE等等。但是这些在Oracle官方文档里并没有说明。