参考：http://blog.csdn.net/frice/article/details/7317744

今天发现一个oracle自带错误查找工具
SQL>  !oerr ora 1555
01555, 00000, "snapshot too old: rollback segment number %s with name \"%s\" too small"
// *Cause: rollback records needed by a reader for consistent read are
//       overwritten by other writers
// *Action: If in Automatic Undo Management mode, increase undo_retention
//          setting. Otherwise, use larger rollback segments


该工具位于$ORACLE_HOME/bin/oerr
该工具所调用的错误信息列表文件为 $ORACLE_HOME/rdbms/mesg/oraus.msg
该工具不可用于windows上，经测试，9i,10g,11g,12c都有此工具。

可通过 sh -x oerr ora 1555 查看脚本执行过程
[oracle@oel6x64 mesg]$ sh -x oerr ora 1555
+ '[' '' = T ']'
+ '[' '!' /u01/app/oracle/12/db1 ']'
+ PERL_DIR=/u01/app/oracle/12/db1/perl
+ PERL_BIN=/u01/app/oracle/12/db1/perl/bin
+ export PERL_BIN
+ /u01/app/oracle/12/db1/perl/bin/perl /u01/app/oracle/12/db1/bin/oerr.pl ora 1555
01555, 00000, "snapshot too old: rollback segment number %s with name \"%s\" too small"
// *Cause: rollback records needed by a reader for consistent read are
//       overwritten by other writers
// *Action: If in Automatic Undo Management mode, increase undo_retention
//          setting. Otherwise, use larger rollback segments
+ exit 0