nocoug 2005 - oracle 10g backup and recovery

8/3/2019 NoCOUG 2005 - Oracle 10g Backup and Recovery

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NoCOUG 2005 Winter Conference

Oracle 10g Backup and Recovery

New Features

Daniel T. Liu

Senior Technical Consultant

First American Real Estate Solutions

Date: Tuesday, February 8, 2005 @ 2:15 PM - 3:15 PM

Venue: Room 103, Oracle Conference Center, Redwood Shores, CA


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NoCOUG 2005, Daniel T. Liu 2

Agenda

Introduction

Oracle Database 10g

Challenges forBackup and Recovery

Types of Database

Errors

Backup and RecoverySolutions


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Agenda

Extended Flashback

Features

Enhanced RMANFeatures

Summary

Q & A


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Introduction to Oracle 10g

Grid Computing Concept Utilizing computing resource as utility

Software level

Hardware level

Grid Computing Challenges

Standardization

Security

Reliability


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Introduction to Oracle 10g

Oracle Database 10g New Features Real Application Clusters

Oracle Streams

Cross-platform transportable tablespaces Automatic Storage Management (ASM)

Self-Managing Database

New Backup and Recovery Features


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Challenges for Backup and Recovery

Database size is getting bigger and bigger Database Backup Time

A DLT tape writes 6 MB/Second, or 21

GB/hour A 2 TB database with one tape driver will

take 97 hours to backup

Database Recovery Time Is the backup good?

Trouble shooting time


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Types of Database Errors

Corruptions Logical corruptions

Physical corruptions

Human Errors

Accidentally drop, or truncate a table Accidentally delete, update rows in a table

Accidentally delete a data file or drop a tablespace

Disasters War, terrorism Earthquake, flood, fire or hurricane

No power for a long period of time

Server crash, malfunction of hardware


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Backup and Recovery Solutions

Logical Methods Export and Import

Data Pump

Flashback Functions

Physical Methods O/S Backup and Restore

RMAN Backup and Restore

High Availability Methods Data Guard RAC

Oracle Streams


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Extended Flashback Functions

Flashback Database Flashback Drop

Flashback Table

Flashback Versions Query

Flashback Transaction Query


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Flashback Database

Traditional recovery method uses backupsand redo log files; Flashback Database isimplemented using a new type of log filecalled Flashback Database logs.

The Oracle database server periodicallylogs before images of data blocks in theFlashback Database logs.

The data block images are used to quicklyback out changes to the database duringFlashback Database.


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Flashback Database

Flashback Database reduces the timerequired to recover the database to a point

in time.

The time to restore a database isproportional to the number of changes that

need to be backed out, not the size of the

database. Flashback Database is faster than

traditional point-in-time recovery.


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Flashback Database

DATABASE

LGWR

FlashbackDatabase

Logs

Redo

LogFiles

RVWR


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Flashback Database

$ ps -ef | grep grid

oracle 25124 1 0 16:32:05 ? 0:00 ora_s000_grid

oracle 25116 1 0 16:32:04 ? 0:00 ora_reco_grid

oracle 25169 1 0 16:32:22 ? 0:00 ora_rvwr_gridoracle 25112 1 0 16:32:04 ? 0:00 ora_ckpt_grid

oracle 25110 1 0 16:32:04 ? 0:00 ora_lgwr_grid

oracle 25108 1 0 16:32:04 ? 0:00 ora_dbw0_grid

oracle 25114 1 0 16:32:04 ? 0:00 ora_smon_grid

oracle 25118 1 0 16:32:04 ? 0:00 ora_cjq0_grid

oracle 25120 1 0 16:32:04 ? 0:00 ora_rbal_grid

oracle 25122 1 0 16:32:04 ? 0:00 ora_d000_grid

oracle 25106 1 0 16:32:04 ? 0:00 ora_pmon_grid

The list below shows all the backgroundprocesses for grid instance.


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Enabling Flashback Database

Make sure the database is in archive mode. Configure the recovery area by setting the two

parameters:

DB_RECOVERY_FILE_DEST

DB_RECOVERY_FILE_DEST_SIZE Open the database in MOUNT EXCLUSIVE

mode and turn on the flashback feature:

SQL> STARTUP MOUNT EXCLUSIVE;

SQL> ALTER DATABASE FLASHBACK ON;

Set the Flashback Database retention target:

DB_FLASHBACK_RETENTION_TARGET


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Disabling Flashback Database

Disabling Flashback DatabaseSQL> ALTER DATABASE FLASHBACK OFF;

Determine if Flashback Database is enabledSQL> select flashback_on

2 from v$database;FLASHBACK_ON------------YES


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Monitoring Flashback Database

Monitoring Flashback DatabaseSQL> select begin_time, flashback_data,2 db_data, redo_data, ESTIMATED_FLASHBACK_SIZE

3 from v$flashback_database_stat;

BEGIN_TIME FLASHBACK_DATA DB_DATA REDO_DATA ESTIMATED_FLASHBACK_SIZE

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

Feb 22 2004 01:05:14 147456 2719744 92160 0

Feb 22 2004 00:05:09 3891200 5857280 2537984 252788736

Feb 21 2004 23:05:04 7979008 13615104 3385344 254877696

Feb 21 2004 22:05:00 14893056 19857408 17463296 255737856

Feb 21 2004 21:04:55 4210688 6422528 2598912 254361600

Feb 21 2004 20:04:51 4333568 8962048 2775552 256475136

Feb 21 2004 19:04:46 4431872 7028736 2804736 258588672

Feb 21 2004 18:04:41 4202496 8511488 2635264 260726784

Feb 21 2004 17:04:37 4030464 6938624 2546688 263012352

Feb 21 2004 16:04:32 4005888 7479296 2512384 265420800Feb 21 2004 15:04:27 3874816 6864896 2471936 267927552Feb 21 2004 14:04:23 4153344 7028736 2578944 270532608Feb 21 2004 13:04:18 3825664 7675904 2497536 27311308813 rows selected.


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Flashback Database Retention

Monitor the Flashback Database retentiontargetSQL> select *

2 from v$flashback_database_log;

OLDEST_FLASHBACK_SCN OLDEST_FLASHBACK_TIMERETENTION_TARGET FLASHBACK_SIZE ESTIMATED_FLASHBACK_SIZE

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

2.2029E+12 Oct 06 2003 09:44:42 144048316416

The default value for flashback retention

time is 1440 minutes.


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Flashback Database

Example 1: Flashback a Database using RMANRMAN> FLASHBACK DATABASE

2> TO TIME = TO_DATE

3> (06/25/03 12:00:00,MM/DD/YY

HH:MI:SS);

Example 2: Flashback a database using SQLcommandSQL> FLASHBACK DATABASE TO TIMESTAMP(SYSDATE 5/24);

SQL> FLASHBACK DATABASE TO SCN 76239;SQL> ALTER DATABASE RESETLOGS;


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Flashback Drop

Prior to Oracle 10g, a DROP commandpermanently removed objects from thedatabase.

SQL> DROP TABLE CUSTOMERS;

In Oracle 10g, a DROP command places theobject in the recycle bin.

The extents allocated to the segment are not

reallocated until you purge the object. You can restore the object from the recycle

bin at any time.


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Recycle Bin

A recycle bin contains all the droppeddatabase objects until,

You permanently drop them with the PURGE

command.

Recover the dropped objects with theFLASHBACK TABLE command.

There is no room in the tablespace for new rows

or updates to existing rows.

The tablespace needs to be extended.


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Recycle Bin

You can view the dropped objects in therecycle bin from two dictionary views:

USER_RECYCLEBIN: list all dropped user

objects

DBA_RECYCLEBIN: list all dropped system-

wide objects


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Example 1: Dropping an ObjectSQL> create table test (col_a varchar(4));Table created.

SQL> select object_name, original_name,

2 type, createtime, droptime3 from user_recyclebin;

no rows selected

SQL> drop table test;

Table dropped.


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Example 1: Dropping an ObjectSQL> select object_name, original_name,2 type, createtime, droptime

3 from user_recyclebin;

OBJECT_NAME ORIGINAL_NAMETYPE CREATETIME DROPTIME

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

BIN$0+ktoVCgEmXgNAAADiUEHQ==$0 TEST

TABLE 2004-02-21:19:04:03 2004-02-21:19:04:41


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Example 1: Dropping an ObjectSQL> create table test (col_b varchar(4));

Table created.

SQL> select object_name, original_name,

2 type, createtime, droptime



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

BIN$0+ktoVCgEmXgNAAADiUEHQ==$0 TESTTABLE 2004-02-21:19:04:03 2004-02-21:19:04:41

SQL> drop table test;

Table dropped.


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Example 1: Dropping an ObjectSQL> select object_name, original_name,2 type, createtime, droptime



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

BIN$0+ktoVChEmXgNAAADiUEHQ==$0 TEST

TABLE 2004-02-21:19:07:33 2004-02-21:19:08:17

BIN$0+ktoVCgEmXgNAAADiUEHQ==$0 TESTTABLE 2004-02-21:19:04:03 2004-02-21:19:04:41


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Example 1: Dropping an ObjectSQL> show recyclebinORIGINAL NAME RECYCLEBIN NAMEOBJECT TYPE DROP TIME

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

--- ------------ -------------------TESTBIN$0+ktoVChEmXgNAAADiUEHQ==$0 TABLE2004-02-21:19:08:17

TESTBIN$0+ktoVCgEmXgNAAADiUEHQ==$0 TABLE2004-02-21:19:04:41


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Example 2: Restoring a Dropped Object

This example will restore a dropped tabletest.

SQL> flashback table

BIN$0+ktoVChEmXgNAAADiUEHQ==$0 to before drop;

Flashback complete.


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Example 3: Dropping a Table Permanently

This statement removes the tablepermanently:SQL> drop table test purge;

Table dropped.

This statement removes the table in the

recycle bin:

SQL> purge table "BIN$0+ktoVChEmXgNAAADiUEHQ==$0";

Table purged.


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Example 4: Dropping a Tablespace

You can only issue this command when thetablespace users is empty. Object in the recycle bin

of tablespace users will be purged:

SQL> drop tablespace users;

When you issue this command, objects in the

tablespace users are dropped. They are not placed

in the recycle bin. Any objects in the recycle bin

belonging to the tablespace users are purged.SQL> drop tablespace users including

contents;


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Example 5: Purging the Recycle Bin

This statement purges the user recycle bin:SQL> purge recyclebin;

Recyclebin purged.

This statement removes all objects from the

recycle bin:SQL> purge dba_recyclebin;

DBA Recyclebin purged.

This statement purges all objects from tablespaceusers in the recycle bin:SQL> purge tablespace users;

Tablespace purged.


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Flashback Table

Flashback Table allows you to recover atable or tables to a specific point in time

without restoring a backup.

When you use the Flashback Table featureto restore a table to a specific point in time,

all associated objects, such as, indexes,

constraints, and triggers will be restored.


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Flashback Table

Flashback Table operations are not validfor the following object types:

Tables that are part of a cluster

Materialized views Advanced Queuing tables

Static data dictionary tables

System tables

Partitions of a table

Remote tables (via database link)


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UNDO_RETENTION Parameter

Data used to recover a table is stored in theundo tablespace. You can use the

parameter UNDO_RETENTION to set the

amount of time you want undo informationretained in the database.

The default value for UNDO_RETENTIONis 900 seconds (15 minutes).


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Guaranteed Retention

When an active transaction uses all the undotablespace, the system will start reusing undo

space that would have been retained unless you

have specified RETENTION GUARANTEE for

the tablespace. To create an undo tablespace with the

RETENTION GUARANTEE option, issue the

following command:SQL> CREATE UNDO TABLEAPCE undo_tbs

DATAFIEL /u02/oradata/grid/undo_tbs01.dbf SIZE 1 G

RETENTION GUARANTEE;


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Flashback Table Privileges

You must have the FLASHBACK TABLEor FLASHBACK ANY TABLE system

privilege to use the Flashback Table feature.


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Example 1: Flashback Table using SCN

Table row movement must be enabled toflashback a table:

SQL> ALTER TABLE billing ENABLE

ROW MOVEMENT; This statement brings a table billing back

to a certain SCN number;

SQL> FLASHBACK TABLE billing TOSCN 76230;


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Example 2: Flashback Table using TIMESTAMP

This statement brings a table billing backto a certain timestamp:SQL> FLASHBACK TABLE billing

TO TIMESTAMPTO_TIMESTAMP(06/25/03

12:00:00,MM/DD/YY HH:MI:SS);


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Flashback Query was first introduced inOracle9i, to provide a way for you to view

historical data.

In Oracle 10g, this feature has beenextended.

You can now retrieve all versions of the

rows that exist or ever existed between thetime the query was issued and a point back

in time.


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You can use the VERSIONS BETWEENclauses to retrieve all historical data related

to a row.

The Flashback Versions Query featureretrieves all committed occurrences of the

row.

The row history data is stored in the undotablespace.


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The undo_retention initialization parameterspecifies how long the database will keep theamount of committed undo information.

If a new transaction needs to use undo space

and there is not enough free space left, anyundo information older than the specifiedundo retention period will be overwritten.

You can set the undo tablespace option toRETENTION GUARANTEE to retain allrow histories.


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Example 1

To verify the retention value for thetablespace, you can issue the followingstatement:

SQL> select tablespace_name, retention

2 From dba_tablespaces;

TABLESPACE_NAME RETENTION

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

SYSTEM NOT APPLY

UNDOTBS1 NOGUARANTEE

SYSAUX NOT APPLY

TEMP NOT APPLY


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Example 2

SQL> create table emp (name varchar2(10),salary number(8,2));

Table created.

SQL> insert into empvalues ('DANIEL',2000);

1 row created.

SQL> commit;

Commit complete.


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Example 2

SQL> update emp set salary = 3000where name = 'DANIEL';

1 row updated.

SQL> commit;

Commit complete.


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Example 2

SQL> select * from emp;NAME SALARY

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

DANIEL 3000

SQL> select * from emp

versions between scn minvalue and maxvalue;

NAME SALARY

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

DANIEL 3000

DANIEL 2000


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It provides a way for you to view changesmade to the database at the transactionlevel.

It allows you to diagnose problems in

your database and perform analysis andaudit transactions.

You can use this feature in conjunction

with the Flash Versions Query feature toroll back the changes made by atransaction.


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You can retrieve the transaction history fromflashback_transaction_query view:Name Null? Type

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

XID RAW(8)

START_SCN NUMBERSTART_TIMESTAMP DATE

COMMIT_SCN NUMBER

COMMIT_TIMESTAMP DATE

LOGON_USER VARCHAR2(30)

UNDO_CHANGE# NUMBER

OPERATION VARCHAR2(32)

TABLE_NAME VARCHAR2(256)

TABLE_OWNER VARCHAR2(32)

ROW_ID VARCHAR2(19)

UNDO_SQL VARCHAR2(4000)


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Example

SQL> select versions_xid, name, salary

2 from emp

3 versions between scn minvalue and maxvalue;

VERSIONS_XID NAME SALARY

---------------- ---------- ----------0003000E00000FE2 DANIEL 3000

DANIEL 2000

SQL> select *2 from flashback_transaction_query

3 where xid = '0003000E00000FE2';


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Example

SQL> select xid, start_scn, start_timestamp,

2 table_name, undo_sql

3 from flashback_transaction_query

4 where xid = '0009001F000000B2;

XID START_SCN START_TIMESTAMPTABLE_NAME

UNDO_SQL

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

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

0009001F000000B2 714980 Feb 21 2004 23:30:31 EMP

update "ORACLE"."EMP" set "SALARY" = 2000' where ROWID ='AAAMWJAAEAAAAFsAAA';


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Summary - Flashback

Flashback Database Flashback Drop

Flashback Table

Flashback Versions Query Flashback Transaction Query


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Enhanced RMAN Features

Automated File Creation DuringRecovery

Simplified Recovery Through Resetlogs Change-Aware Incremental Backups

Automated Disk-Based Backup and

Recovery RMAN Database Dropping and

Deregistration


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Automated File Creation During Recovery

This feature enhances RMAN recoveryby automatically creating and recoveringdatafiles that have never been backed up.

In order to recover a data file that has

never been backed up, you need thearchive log files from the time of the datafile creation until the time at which you

want to stop the recovery process and acopy of the control file with theinformation regarding the data file.


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Automated File Creation During Recovery

data file

#1

data file

#2

Missing

data file

#3

Control fle

RMAN

Archive log files


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Simplified Recovery Through Resetlogs

After performing an incomplete (Point-in-time) recovery, you need to open the

database with RESETLOGS option:

SQL> alter database open resetlogs;


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This RESETLOGS operation creates a newincarnation of the database and resets the logs.

Prior to Oracle 10g, the newly generated redolog files could not be used with the backups

taken in the past. Therefore, it was importantto take an immediate backup since all previousbackups became invalid.

In addition, if you used RMAN catalog for

future backups, you needed to issue thefollowing command to make the RMAN catalogaware of the new incarnation of the database.

RMAN> reset database;


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In Oracle 10g, you no longer have to backup your database following an incompleterecovery and OPEN RESETLOGSoperations.

This new feature is also applicable to thefollowing two scenarios: When you perform a recovery using a

backup control file and open the databasewith the RESETLOGS operation.

When you need to reinstantiate the oldprimary database following a failover.


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Benefits of Simplified Recovery ThroughResetlogs

There is no need to perform a full backup

after an incomplete recovery.

There is no need to recreate a new standby

database after a failover operation.

There is no need to change any backup

scripts as there are no changes to therecovery commands to take advantage of

this functionality.


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Benefits of Simplified Recovery ThroughResetlogs

You can take incremental backups based on

full backups of a previous incarnation when

you use RMAN.

Block media recovery can restore backups

from parent incarnation backups and

recover the corrupted blocks through aRESETLOGS operation.


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How does it work? Oracle 10g introduces a new format

specification for archived log files.

This new format avoids overwriting archived

redo log files with the same sequencenumber across incarnations.

SQL> show parameter log_archive_format

NAME TYPE VALUE

---------------------------- ----------- ------------log_archive_format string %t_%s_%r.dbf


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The format specification is %r andrepresents the resetlogs id. It is included

in the default format for the

LOG_ARCHIVE_FORMATinitialization parameter.

It will ensure that a unique name is

constructed for the archived redo log file

during RMAN restore and SQL*plusauto recovery mode.


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During the RESETLOGS operation, theinformation in V$LOG_HISTORY and

V$OFFLINE_RANGE records are no

longer cleared.

In addition, two new columns have been

added to indicate the incarnation the

records belong to:

RESETLOGS_CHANGE#

RESETLOGS_TIME.


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SQL> select recid, thread#, sequence#, resetlogs_change#,resetlogs_time

2 from v$log_history3 where rownum < 20;

RECID THREAD# SEQUENCE# RESETLOGS_CHANGE# RESETLOGS_TIME

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

1 1 1 1 Aug 12 2003 18:48:54

2 1 2 1 Aug 12 2003 18:48:54

3 1 3 1 Aug 12 2003 18:48:544 1 4 1 Aug 12 2003 18:48:54

5 1 5 1 Aug 12 2003 18:48:54

6 1 6 1 Aug 12 2003 18:48:54

7 1 7 1 Aug 12 2003 18:48:54

8 1 8 1 Aug 12 2003 18:48:54

9 1 9 1 Aug 12 2003 18:48:54

10 1 10 1 Aug 12 2003 18:48:5411 1 11 1 Aug 12 2003 18:48:54

12 1 12 1 Aug 12 2003 18:48:54

13 1 13 1 Aug 12 2003 18:48:54

14 1 14 1 Aug 12 2003 18:48:54

15 1 15 1 Aug 12 2003 18:48:54

Ch A I l B k


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Change-Aware Incremental Backups

In previous releases of the Oracle database,when you perform an incremental backup,

RMAN has to examine every block in the data

file to determine which blocks have been

changed. The time to perform an incremental backup is

proportional to the size of the data files.

Therefore, to perform an incremental backup

on a very large database can take some timeeven if you have just changed a few blocks.

Ch A I l B k


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In Oracle 10g, you can create ablock changetracking file that records the blocks modified

since the last backup.

RMAN uses the tracking file to determine

which blocks to include in the incrementalbackup.

RMAN no longer needs to examine the entire

data file. The time to perform an incremental

backup is now proportional to the amount of

content modified since the last backup.

Ch A I t l B k


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Here are the steps RMAN will perform todo an incremental backup:

Read the Block Change Tracking File to

determine which blocks in the data file need

to be read.

Only scan the changed blocks in the data file

and then back them up.

Ch A I t l B k


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Block Change Tracking File

Data File

RMAN Step 1

Step 2

Ch A I t l B k


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How big is the Block Change Tracking File? The database size in bytes: theblock change tracking

file contains data representing every data file block

in the database. The data is approximately 1/250000

of the total size of the database.

The number of enabled threads: In a Real

Application Cluster (RAC) environment, the

instances update different areas of the tracking file

without any locking or inter-node block swapping.

You enable block change tracking for the entiredatabase and not for individual instances.

Ch A I t l B k


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How big is the Block Change TrackingFile?

The number of old backups: The block

change tracking file keeps a record of all

changes between previous backups, inaddition to the modification since the last

backup. It retains the change history for a

maximum of eight backups.

Ch A I t l B k


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The size of the file is calculated by thefollowing formula:

Size of the Block Change

Tracking File =( ( (Threads*2) + number of oldbackups ) * database size inbytes ) / 250,000

Ch A I t l B k


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The minimum size for the block changetracking file is 10 MB.

By using this formula, a 2 TB database

with only one thread, and having fivebackups in the RMAN repository will

require a block change tracking file of 59

MB.

Ch A I t l B k


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Enabling Block Change Tracking By default, Oracle will not record block

change information.

To enable this feature, you need to issue the

following command:

SQL> alter database enable blockchange tracking;

Ch A I t l B k


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Disabling Block Change TrackingSQL> alter database disable blockchange tracking;

Monitoring the status of Block Change

Tracking:SQL> select file, status, bytes

2 from v$block_change_tracking;

STATUS FILE BYTES----------- ---------------------------- ---------------

ENABLED /dba/backup/01_mf_yzmrr7.chg 10,000,000



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p

Recovery

Prior to Oracle 10g, disk files that were createdby RMAN utility or ARCH process had noknowledge of one another.

Furthermore, they were not aware of the sizesof the file system on which they created files.Database administrators need to routinelyclean up the old archive logs or old RMANfiles.

It is nice to have a unified disk storage locationwhere you can manage all recovery relatedfiles. Now you can achieve this in Oracle 10gby specifying aRecovery Area



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p

Recovery

Therecovery area is a unified disk storagelocation for all recovery related files and

activities in an Oracle Database. Those files

include:

Control file

Online redo log files

Archived log files

Flashback logs

Control file autobackups

Data file copies RMAN files



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p

Recovery

The recovery area is defined by settingtwo initialization parameters. These two

parameters can be dynamically altered or

disabled.

Thedb_recovery_file_dest_size sets the disk

limit, expressed in bytes

Thedb_recovery_file_dest sets the location

for the recovery area



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p

Recovery

Set the disk limit for recovery area to 100GB:SQL> ALTER SYSTEM SET

DB_RECOVERY_FILE_DEST_SIZE = 100G;

Set the recovery area destination:

SQL> ALTER SYSTEM SET

DB_RECOVERY_FILE_DEST = /dba/backup/;



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Recovery

Alter a Recovery AreaSQL> ALTER SYSTEM SETDB_RECOVERY_FILE_DEST_SIZE = 200G;

Disabling a Recovery AreaSQL> ALTER SYSTEM SETDB_RECOVERY_FILE_DEST = ;



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Recovery

Recovery Area Space Management When the recovery area is less than 90% full, Oracle

does not delete eligible files immediately, to

minimize the need to restore recent files from tape

during recovery. The recovery area can thus serve

as a kind of cache for tape.

Once the recovery area is 90% full, Oracle will issue

a warning to users.

The Oracle database server and RMAN will

continue to create files in the recovery area until

100% of the disk limit is reached.



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Recovery

Recovery Area Space Management

Once the recovery area is 100% full, the RMAN

retention policy is used to indicate what files will be

deleted in order to make space for newer files.

The db_flashback_retention_target parameterspecifies how long Oracle will keep the flashback

logs in the flashback recovery area. However,

flashback logs won't be deleted even if it exceeds the

duration specified by the flashback retention period

unless more space is needed in the recovery area forother files.



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Recovery

New RMAN command for RecoveryArea

RMAN> BACKUP RECOVERY AREA;

RMAN> BACKUP RECOVERY FILES;



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Recovery

Oracle 10g has a new dynamic performance

view for monitoring the recovery area:

SQL> desc v$recovery_file_dest

Name Null? Type

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

NAME VARCHAR2(513)

SPACE_LIMIT NUMBER

SPACE_USED NUMBER

SPACE_RECLAIMABLE NUMBERNUMBER_OF_FILES NUMBER



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Recovery

Example:SQL> select * from v$recovery_file_dest;

NAME SPACE_LIMIT SPACE_USED

SPACE_RECLAIMABLE NUMBER_OF_FILES------------ ------------- ----------------------------- ----------------

/dba/backup 2147483648 458219520

0 49

RMAN Database Dropping and


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Deregistration

In Oracle 10g, you can drop a database and

remove its entry from the RMAN catalog.

The following statement drops the entiredatabase and removes the database files:RMAN> drop database;

The following statement drops the entire

database, removes the database files, and deletes

all backup copies of the database and the archivelog files:RMAN> drop database including backups;

RMAN Database Dropping and


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Deregistration

The above two statements drop thedatabase and delete the database files.

However, they do not unregister the

database from the RMAN catalog. The

following statement will remove the

database information from the RMAN

catalog:

RMAN> unregister database grid;

S RMAN F t


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Summary - RMAN Features

Automated File Creation DuringRecovery

Simplified Recovery Through Resetlogs Change-Aware Incremental Backups

Automated Disk-Based Backup andRecovery

RMAN Database Dropping andDeregistration

Summary


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Summary

Oracle Database 10g Grid Computing

Challenges For Backup and Recovery

Different Types of Database Errors Solutions for Backup and Recovery

Oracle 10g Extended Flashback Features

Oracle 10g Enhanced RMAN Features


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Questions

&

Answers


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References

Oracle Database 10g New Features, Ault, Liu and Tumma;

Rampant Techpress;

Recovery Manager Reference, 10g Release;

Backup and Recovery Advanced Users Guide, 10g Release;

I would also like to acknowledge the assistance of Larry

Bailey of FARES, Tammy Bednar, Larry Carpenter, Roger

Peterson, Schwinn Ulrike of Oracle Corporation.


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Thanks For Coming !!

Daniel Liu Contact Information

Phone: (714) 701-3346

Email: [email protected]

Email: [email protected]

Company Web Site:

http://www.firstam.com

nocoug 2005 - oracle 10g backup and recovery

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