2012-10-22 11gR2"2DAY DBA"page126-280 & "ADMINISTRATOR'S GUIDE" page1-61

Large object (LOB) columns are used to contain unstructured data (such as text or

streaming video), and can hold terabytes of information. In Oracle Database 11g, you

can use SecureFiles, the next generation LOB data type, which provide high

performance, easier manageability, and full backward compatibility with existing LOB

interfaces. SecureFiles also offer advanced features such as intelligent data

compression, deduplication and transparent encryption. The LOB implementation

available in Oracle Database 10g Release 2 and prior releases is still supported for

backward-compatibility reasons and is now referred to as BasicFiles. If you add a LOB

column to a table, then you can specify whether it should be created as a SecureFile or

a BasicFile. If you do not specify the storage type, then the LOB is created as a

BasicFile to ensure backward compatibility.

此版本的LOB使用了SECUREFILE（之前版本是BASICFILE），可以提供更好的特性。

Synonyms

Because a synonym is simply an alias, it requires no storage other than its

definition in the data dictionary. To reference a synonym in a query, you must have

privileges on the object to which it points. Synonyms themselves cannot be

secured. If you grant object privileges on a synonym to a user, then you are

granting privileges on the object to which the synonym points.

一旦你将SYNONYM的访问权限赋予某个用户，也就相当于你把SYNONYM所指向的对象的权限赋予了此用户，

这在赋权的时候要注意。

RMAN Backup Concepts

Incremental Backups of Data Files

RMAN incremental backups copy only those blocks in a data file that change between

backups. A level 0 incremental backup, which copies all blocks in the data file, is used

as a starting point for an incremental backup strategy.

Incremental backups at level 1 copy only images of blocks that have changed since a

previous incremental backup. Level 1 backups can be cumulative, in which case all

blocks changed since the most recent level 0 backup are included, or differential, in

which case only blocks changed since the most recent level 0 or level 1 incremental

backup are included. A typical incremental strategy makes level 1 backups at regular

intervals such as once each day.

简单来说，增量备份就是自上一次全备之后的备份，差分就是自上一次全备或上一次增量的备份。

Using the Oracle Suggested Backup Strategy

About the Oracle Suggested Backup Strategy

The Oracle suggested strategy is based on

creating an image copy of your database. The database rolls forward this copy by

using incrementally updated backups. Oracle Enterprise Manager schedules RMAN

backup jobs during the overnight hours.

你可以使用Oracle给你的备份建议，第一天先做一个COPY级别的全备，之后增量备份，当你需要恢复的时候，

你可以把增量备份一起混合进第一天的全备，减少恢复的时间。

脚本类似如下（脚本仅包含将增量备份混合进COPY级别的全备）：

Daily Script:

run {

allocate channel oem_disk_backup device type disk;

recover copy of database with tag 'ORA_OEM_LEVEL_0';

backup incremental level 1 copies=1 for recover of copy with tag

'ORA_OEM_LEVEL_0' database;

}

Deleting Expired Backups

Deleting expired backups removes from the RMAN repository those backups that are

listed as EXPIRED. Expired backups are those found to be inaccessible during a

cross-check. No attempt is made to delete the files containing the backup from disk or

tape; this action updates only the RMAN repository.

Deleting Obsolete Backups

This section explains how to delete obsolete backups, which are those no longer

needed by the configured retention policy. If you use a fast recovery area as your only

disk-based backup destination, then you never have to delete obsolete backups from

disk. The fast recovery area keeps files as specified by the retention policy, and deletes

them only when space is needed.

这里比较一下EXPIRED与OBSOLETE的差别，EXPIRED指的是CROSSCHECK完已不存在磁盘的备份，

PBSOLETE指的是已不在RETENTION POLICY所指定的范围内的备份。

Removing Oracle Database Software

If you want to remove an Oracle software installation, you can use the Deinstallation

tool to completely uninstall the software from your computer.

The Deinstallation Tool (deinstall) is available in Oracle home directories after

installation as $ORACLE_HOME/deinstall/deinstall.

你可以使用Oracle自带的脚本删除Oracle软件。

如下：

To remove an Oracle home from your computer:

1. Execute the Deinstallation tool. The command you enter depends on whether you

are executing the tool from an installed Oracle home or executing the tool after

downloading it from OTN. Do one of the following:

If you are executing the tool from an installed Oracle home, the following is an

example of the commands you would enter:

$ cd /u01/app/oracle

$ product/11.2.0/dbhome_1/deinstall/deinstall

If you are executing the tool after downloading and unzipping the archive file

from OTN, enter the following command (replacing Oracle_home with the full

path name for your Oracle home):

$ deinstall -home Oracle_home

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ADMINISTRATOR'S GUIDE

Identifying Your Oracle Database Software Release -- Oracle版本号的解释

Release Number Format



Checking Your Current Release Number -- 检查当前版本

COL PRODUCT FORMAT A40

COL VERSION FORMAT A15

COL STATUS FORMAT A15

SELECT * FROM PRODUCT_COMPONENT_VERSION;

PRODUCT VERSION STATUS

---------------------------------------- ----------- -----------

NLSRTL 11.2.0.0.1 Production

Oracle Database 11g Enterprise Edition 11.2.0.0.1 Production

PL/SQL 11.2.0.0.1 Production

Administrative Privileges

SYSDBA and SYSOPER --- SYSDBA与SYSOPER权限的总结