RMAN备份过程中调整系统时间的BUG

今天检查RMAN备份脚本的执行情况时发现了错误信息。

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of crosscheck command at 08/15/2006 09:18:29
ORA-01455: converting column overflows integer datatype

检查后发现，备份操作没有失败，而是在CROSSCHECK BACKUPSET命令和DELETE NOPROMPT OBSOLETE命令时出现的错误。

使用RMAN直接查询，错误同上。

到metalink上查询了一下，发现和ORA-1455错误相关的Oracle bug还真是不少。有的是由于序列的值过大，有的是由于记录中的变量定义太小，有的是由于备份时时间向前调整。

由于是测试数据库，采用NOCATALOG方式，而使用NOCATALOG方式，metalink上给的许多诊断方式都无法使用。而在rman下通过命令查询，却大部分都报ORA-1455的错误。只能为数据库建立一个CATALOG，建立CATALOG后登陆数据库进行查询，发现：

SQL> select piece#, bp_key, start_time, completion_time
2 from rc_backup_piece
3 where start_time > completion_time;

PIECE# BP_KEY START_TIME COMPLETION_TIME
---------- ---------- ------------------- -------------------
1 493 2006-08-10 09:18:38 2006-08-10 09:18:36

由此，可以断定是由于时间变化导致结束时间比开始时间早，导致了问题。

根据metalink上面介绍的方式，删除BACKUPPIECE：

SQL> select handle from rc_backup_piece where start_time > completion_time;

HANDLE
--------------------------------------------------
/data1/backup/testdata/c-2270762593-20060810-00

[oracle@demo2 oracle]$ rman target / catalog "rman/rman@testcen"

Recovery Manager: Release 9.2.0.4.0 - Production

connected to target database: TESTDATA (DBID=2270762593)
connected to recovery catalog database

RMAN> delete backuppiece '/data1/backup/testdata/c-2270762593-20060810-00';

allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=16 devtype=DISK

List of Backup Pieces
BP Key BS Key Pc# Cp# Status Device Type Piece Name
IXDBA.NET技术社区
------- ------- --- --- ----------- ----------- ----------
493 413 1 1 AVAILABLE DISK /data1/backup/testdata/c-2270762593-20060810-00

Do you really want to delete the above objects (enter YES or NO)? yes
deleted backup piece
backup piece handle=/data1/backup/testdata/c-2270762593-20060810-00 recid=691 stamp=598094318
Deleted 1 objects

至此问题已经解决：

RMAN> delete noprompt obsolete;

RMAN retention policy will be applied to the command
RMAN retention policy is set to recovery window of 7 days
using channel ORA_DISK_1
Deleting the following obsolete backups and copies:
Type Key Completion Time Filename/Handle
-------------------- ------ ------------------ --------------------
Backup Set 387 02-8月 -06
Backup Piece 467 02-8月 -06 /data1/backup/testdata/c-2270762593-20060802-00
Backup Set 393 03-8月 -06
Backup Piece 473 03-8月 -06 /data1/backup/testdata/c-2270762593-20060803-00
deleted backup piece
backup piece handle=/data1/backup/testdata/c-2270762593-20060802-00 recid=665 stamp=597403426