每天的定时JOB今天执行的很慢，查了下日志，发现了问题。
Thu Jan 09 09:13:23 2014
ARC0: Warning.  Log sequence in archive filename wrapped
to fix length as indicated by %S in LOG_ARCHIVE_FORMAT.
Old log archive with same name might be overwritten.
Thu Jan 09 09:13:43 2014
Thread 1 advanced to log sequence 315239
  Current log# 1 seq# 315239 mem# 0: D:\ORACLE\PRODUCT\10.2.0\ORADATA\AGENCY\REDO01.LOG


查了下，需要修改LOG_ARCHIVE_FORMAT参数。


C:\Documents and Settings\dba>sqlplus sys/ as sysdba


SQL*Plus: Release 10.2.0.1.0 - Production on Fri Jan 10 06:29:30 2014


Copyright (c) 1982, 2005, Oracle.  All rights reserved.


Enter password:


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options


SQL> show parameter log_archive_format


NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_format                   string      ARC%S_%R.%T
SQL> alter system set log_archive_format='ARC%s_%R.%T' scope=spfile;


System altered.


SQL> show parameter log_archive_format


NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_format                   string      ARC%S_%R.%T
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.


Total System Global Area 1.7180E+10 bytes
Fixed Size                  2034464 bytes
Variable Size             486540512 bytes
Database Buffers         1.6677E+10 bytes
Redo Buffers               14741504 bytes
Database mounted.
Database opened.
SQL> show parameter log_archive_format


NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
log_archive_format                   string      ARC%s_%R.%T