今天对Oracle数据库升级做了大致了解，还是很多东西值得考虑的。 首先，升级前的准备就很多工作需要做： 1. 测试和准备， 主要是

今天对Oracle数据库升级做了大致了解，还是很多东西值得考虑的。

首先，升级前的准备就很多工作需要做：

1. 测试和准备， 主要是应用的做压力测试。因为版本升级，，优化器可能使SQL性能回退（选择性能更差的执行计划），可以结合database replay做压力测试，SPA模拟环境变化的影响，以及SPM对执行计划做固定。

2. 升级的方法， 主要是图形界面DBUA（新目录的路径）来完成，相对简单；手工升级（手工执行脚本、DBUA只不过将这些手工动作代替而已、新目录路径）；EXPDP（源库路径）/IMPDP（新库路径）等等。

其中，以下几种方法可以支持滚动升级：

可以看得出，升级的方案多样，根据不同的环境而定。

3. 升级前，务必将新库路径下$ORACLE_HOME/rdbms/admin/utlu112i.sql脚本拷至源库执行，主要是检查当前环境（如表空间大小，隐含参数，警告或建议）是否合适做升级，我们可以根据警告和建议做相应调整。

以下粘出单机数据库的升级实验步骤，供参数，由10.2.0.5升级至11.2.0.3.

时间允许的话,将做RAC的升级并更新文章

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一、源库--备份

run {
allocate channel ch1 device type disk;
allocate channel ch2 device type disk;
allocate channel ch3 device type disk;
allocate channel ch4 device type disk;
backup AS BACKUPSET full tag 'db_full' format '/backup/db_%d_%T_%s_%U.bak' database include current controlfile;
sql 'alter system archive log current';
release channel ch4;
release channel ch3;
release channel ch2;
release channel ch1;
}

SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /arch/ora10g
Oldest online log sequence 49
Next log sequence to archive 51
Current log sequence 51

二、源库 -- 运行脚本utlu112i.sql,做升级前检查
[oracle@tivoli02 backup]$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.5.0 - Production on Mon Jan 26 20:27:42 2015

Copyright (c) 1982, 2010, Oracle. All Rights Reserved.

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> spool /tmp/upgrade_info.log
@/u01/app/oracle/product/11.2.0/db_1/rdbms/admin/utlu112i.sql

打印内容如下:
================
SQL> @/u01/app/oracle/product/11.2.0/db_1/rdbms/admin/utlu112i.sql
Oracle Database 11.2 Pre-Upgrade Information Tool 01-26-2015 20:34:56
Script Version: 11.2.0.3.0 Build: 001
.
**********************************************************************
Database:
**********************************************************************
--> name: ORA10G
--> version: 10.2.0.5.0
--> compatible: 10.2.0.5.0
--> blocksize: 8192
--> platform: Linux x86 -bit
--> timezone file: V4
.
**********************************************************************
Tablespaces: [make adjustments in the current environment]
**********************************************************************
--> SYSTEM tablespace is adequate for the upgrade.
.... minimum required size: 3 MB
--> UNDOTBS1 tablespace is adequate for the upgrade.
.... minimum required size: 400 MB
--> SYSAUX tablespace is adequate for the upgrade.
.... minimum required size: 433 MB
--> TEMP tablespace is adequate for the upgrade.
.... minimum required size: 60 MB
.
**********************************************************************
Flashback: OFF
**********************************************************************
**********************************************************************
Update Parameters: [Update Oracle Database 11.2 init.ora or spfile]
Note: Pre-upgrade tool was run on a lower version -bit database.
**********************************************************************
--> If Target Oracle is 32-Bit, refer here for Update Parameters:
-- No update parameter changes are required.
.

--> If Target Oracle is -Bit, refer here for Update Parameters:
-- No update parameter changes are required.
.
**********************************************************************
Renamed Parameters: [Update Oracle Database 11.2 init.ora or spfile]
**********************************************************************
-- No renamed parameters found. No changes are required.
.
**********************************************************************
Obsolete/Deprecated Parameters: [Update Oracle Database 11.2 init.ora or spfile]
**********************************************************************
--> sql_trace 10.2 DEPRECATED
--> background_dump_dest 11.1 DEPRECATED replaced by "diagnostic_dest"
--> user_dump_dest 11.1 DEPRECATED replaced by "diagnostic_dest"
.