nocoug 2005 winter conference nocoug 2005 winter conference oracle 10g backup and recovery new...

NoCOUG 2005 Winter Conference NoCOUG 2005 Winter Conference Oracle 10g Backup and Recovery

New Features

Daniel T. LiuSenior 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

NoCOUG 2005, Daniel T. Liu 2

Agenda

• Introduction– Oracle Database 10g

– Challenges for Backup and Recovery

– Types of Database Errors

– Backup and Recovery Solutions


Agenda

• Extended Flashback Features

• Enhanced RMAN Features

• Summary• Q & A


Introduction to Oracle 10g

• Grid Computing Concept– Utilizing computing resource as utility– Software level– Hardware level

• Grid Computing Challenges– Standardization– Security– Reliability


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


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


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


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


Extended Flashback Functions

• Flashback Database

• Flashback Drop

• Flashback Table

• Flashback Versions Query

• Flashback Transaction Query


Flashback Database

• Traditional recovery method uses backups and redo log files; Flashback Database is implemented using a new type of log file called Flashback Database logs.

• The Oracle database server periodically logs before images of data blocks in the Flashback Database logs.

• The data block images are used to quickly back out changes to the database during Flashback Database.


Flashback Database

• Flashback Database reduces the time required to recover the database to a point in time.

• The time to restore a database is proportional 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.


Flashback Database

DATABASE

LGWR

FlashbackDatabase

Logs

RedoLogFiles

RVWR


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_grid oracle 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 background processes for ‘grid’ instance.


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


Disabling Flashback Database

• Disabling Flashback DatabaseSQL> ALTER DATABASE FLASHBACK OFF;

• Determine if Flashback Database is enabled

SQL> select flashback_on

2 from v$database;

FLASHBACK_ON

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

YES


Monitoring Flashback Database• Monitoring Flashback Database

SQL> 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 0Feb 22 2004 00:05:09 3891200 5857280 2537984 252788736Feb 21 2004 23:05:04 7979008 13615104 3385344 254877696Feb 21 2004 22:05:00 14893056 19857408 17463296 255737856Feb 21 2004 21:04:55 4210688 6422528 2598912 254361600Feb 21 2004 20:04:51 4333568 8962048 2775552 256475136Feb 21 2004 19:04:46 4431872 7028736 2804736 258588672Feb 21 2004 18:04:41 4202496 8511488 2635264 260726784Feb 21 2004 17:04:37 4030464 6938624 2546688 263012352Feb 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 273113088 13 rows selected.


Flashback Database Retention

• Monitor the Flashback Database retention targetSQL> select *

2 from v$flashback_database_log;

OLDEST_FLASHBACK_SCN OLDEST_FLASHBACK_TIME RETENTION_TARGET FLASHBACK_SIZE ESTIMATED_FLASHBACK_SIZE

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

2.2029E+12 Oct 06 2003 09:44:42 1440 48316416

• The default value for flashback retention time is 1440 minutes.


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 SQL commandSQL> FLASHBACK DATABASE TO TIMESTAMP (SYSDATE – 5/24);

SQL> FLASHBACK DATABASE TO SCN 76239;

SQL> ALTER DATABASE RESETLOGS;


Flashback Drop

• Prior to Oracle 10g, a DROP command permanently removed objects from the database.SQL> DROP TABLE CUSTOMERS;

• In Oracle 10g, a DROP command places the object 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.


Recycle Bin

• A recycle bin contains all the dropped database objects until,– You permanently drop them with the PURGE

command.– Recover the dropped objects with the

FLASHBACK TABLE command.– There is no room in the tablespace for new rows

or updates to existing rows.– The tablespace needs to be extended.


Recycle Bin

• You can view the dropped objects in the recycle bin from two dictionary views:– USER_RECYCLEBIN: list all dropped user

objects– DBA_RECYCLEBIN: list all dropped system-

wide objects


Example 1: Dropping an Object

SQL> create table test (col_a varchar(4));

Table created.

SQL> select object_name, original_name,

2 type, createtime, droptime

3 from user_recyclebin;

no rows selected

SQL> drop table test;

Table dropped.



SQL> select object_name, original_name,

2 type, createtime, droptime

3 from user_recyclebin;

OBJECT_NAME ORIGINAL_NAME TYPE CREATETIME DROPTIME

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

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



SQL> create table test (col_b varchar(4));Table created. SQL> select object_name, original_name, 2 type, createtime, droptime 3 from user_recyclebin; OBJECT_NAME ORIGINAL_NAME TYPE

CREATETIME DROPTIME------------------------------ ----------------

------ ------------------- ------------------- BIN$0+ktoVCgEmXgNAAADiUEHQ==$0 TEST

TABLE 2004-02-21:19:04:03 2004-02-21:19:04:41 SQL> drop table test;Table dropped.



SQL> select object_name, original_name, 2 type, createtime, droptime 3 from user_recyclebin;OBJECT_NAME ORIGINAL_NAME 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 TEST TABLE 2004-02-21:19:04:03 2004-02-21:19:04:41



SQL> show recyclebin

ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME

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

TEST BIN$0+ktoVChEmXgNAAADiUEHQ==$0 TABLE 2004-02-21:19:08:17

TEST BIN$0+ktoVCgEmXgNAAADiUEHQ==$0 TABLE 2004-02-21:19:04:41


Example 2: Restoring a Dropped Object

• This example will restore a dropped table test.

SQL> flashback table “BIN$0+ktoVChEmXgNAAADiUEHQ==$0” to before drop;

Flashback complete.


Example 3: Dropping a Table Permanently

• This statement removes the table permanently: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.


Example 4: Dropping a Tablespace

• You can only issue this command when the tablespace 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;


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 tablespace

users in the recycle bin:SQL> purge tablespace users;Tablespace purged.


Flashback Table

• Flashback Table allows you to recover a table or tables to a specific point in time without restoring a backup.

• When you use the Flashback Table feature to restore a table to a specific point in time, all associated objects, such as, indexes, constraints, and triggers will be restored.


Flashback Table

• Flashback Table operations are not valid for 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)


UNDO_RETENTION Parameter

• Data used to recover a table is stored in the undo tablespace. You can use the parameter UNDO_RETENTION to set the amount of time you want undo information retained in the database.

• The default value for UNDO_RETENTION is 900 seconds (15 minutes).


Guaranteed Retention

• When an active transaction uses all the undo tablespace, 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;


Flashback Table Privileges

• You must have the FLASHBACK TABLE or FLASHBACK ANY TABLE system privilege to use the Flashback Table feature.


Example 1: Flashback Table using SCN

• Table row movement must be enabled to flashback 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 TO SCN 76230;


Example 2: Flashback Table using TIMESTAMP

• This statement brings a table ‘billing’ back to a certain timestamp:

SQL> FLASHBACK TABLE billing

TO TIMESTAMP

TO_TIMESTAMP(‘06/25/03 12:00:00’,’MM/DD/YY HH:MI:SS’);


Flashback Versions Query

• Flashback Query was first introduced in Oracle9i, to provide a way for you to view historical data.

• In Oracle 10g, this feature has been extended.

• You can now retrieve all versions of the rows that exist or ever existed between the time the query was issued and a point back in time.



• You can use the VERSIONS BETWEEN clauses to retrieve all historical data related to a row.

• The Flashback Versions Query feature retrieves all committed occurrences of the row.

• The row history data is stored in the undo tablespace.



• The undo_retention initialization parameter specifies how long the database will keep the amount of committed undo information.

• If a new transaction needs to use undo space and there is not enough free space left, any undo information older than the specified undo retention period will be overwritten.

• You can set the undo tablespace option to RETENTION GUARANTEE to retain all row histories.


Example 1

• To verify the retention value for the tablespace, you can issue the following statement:

SQL> select tablespace_name, retention 2 From dba_tablespaces; TABLESPACE_NAME RETENTION------------------------------ -----------SYSTEM NOT APPLYUNDOTBS1 NOGUARANTEESYSAUX NOT APPLYTEMP NOT APPLY


Example 2

SQL> create table emp (name varchar2(10),

salary number(8,2));

Table created.

SQL> insert into emp

values ('DANIEL',2000);

1 row created.

SQL> commit;

Commit complete.


Example 2

SQL> update emp set salary = 3000

where name = 'DANIEL';

1 row updated.

SQL> commit;

Commit complete.


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


Flashback Transaction Query

• It provides a way for you to view changes made to the database at the transaction level.

• It allows you to diagnose problems in your database and perform analysis and audit transactions.

• You can use this feature in conjunction with the Flash Versions Query feature to roll back the changes made by a transaction.


Flashback Transaction Query

• You can retrieve the transaction history from flashback_transaction_query view:

Name Null? Type

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

XID RAW(8)

START_SCN NUMBER

START_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)


ExampleSQL> 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';


ExampleSQL> select xid, start_scn, start_timestamp, 2 table_name, undo_sql 3 from flashback_transaction_query 4 where xid = '0009001F000000B2‘; XID START_SCN START_TIMESTAMP

TABLE_NAME UNDO_SQL---------------- ---------- --------------------

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

----------------------0009001F000000B2 714980 Feb 21 2004 23:30:31 EMPupdate "ORACLE"."EMP" set "SALARY" = ‘2000' where ROWID =

'AAAMWJAAEAAAAFsAAA';


Summary - Flashback

• Flashback Database

• Flashback Drop

• Flashback Table

• Flashback Versions Query

• Flashback Transaction Query


Enhanced RMAN Features

• Automated File Creation During Recovery

• Simplified Recovery Through Resetlogs• Change-Aware Incremental Backups• Automated Disk-Based Backup and

Recovery• RMAN Database Dropping and

Deregistration


Automated File Creation During Recovery

• This feature enhances RMAN recovery by automatically creating and recovering datafiles that have never been backed up.

• In order to recover a data file that has never been backed up, you need the archive log files from the time of the data file creation until the time at which you want to stop the recovery process and a copy of the control file with the information regarding the data file.


Automated File Creation During Recovery

data file#1

data file#2

Missingdata file

#3

Control fle

RMAN

Archive log files


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;



• This RESETLOGS operation creates a new incarnation of the database and resets the logs.

• Prior to Oracle 10g, the newly generated redo log files could not be used with the backups taken in the past. Therefore, it was important to take an immediate backup since all previous backups became invalid.

• In addition, if you used RMAN catalog for future backups, you needed to issue the following command to make the RMAN catalog aware of the new incarnation of the database. RMAN> reset database;



• In Oracle 10g, you no longer have to back up your database following an incomplete recovery and OPEN RESETLOGS operations.

• This new feature is also applicable to the following two scenarios:– When you perform a recovery using a

backup control file and open the database with the RESETLOGS operation.

– When you need to reinstantiate the old primary database following a failover.



• Benefits of Simplified Recovery Through Resetlogs– 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 the recovery commands to take advantage of this functionality.



• Benefits of Simplified Recovery Through Resetlogs– 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 a RESETLOGS operation.



• 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 sequence number across incarnations.

SQL> show parameter log_archive_format

NAME TYPE VALUE

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



• The format specification is %r and represents the resetlogs id. It is included in the default format for the LOG_ARCHIVE_FORMAT initialization parameter.

• It will ensure that a unique name is constructed for the archived redo log file during RMAN restore and SQL*plus auto recovery mode.



• During the RESETLOGS operation, the information 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.



SQL> select recid, thread#, sequence#, resetlogs_change#,resetlogs_time 2 from v$log_history 3 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 18:48:54 4 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 18:48:54 11 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


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 time even if you have just changed a few blocks.



• In Oracle 10g, you can create a block change tracking file that records the blocks modified since the last backup.

• RMAN uses the tracking file to determine which blocks to include in the incremental backup.

• 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.



• Here are the steps RMAN will perform to do 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.



Block Change Tracking File

Data File

RMAN Step 1

Step 2



• How big is the Block Change Tracking File?– The database size in bytes: the block 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 entire database and not for individual instances.



• How big is the Block Change Tracking File?– The number of old backups: The block

change tracking file keeps a record of all changes between previous backups, in addition to the modification since the last backup. It retains the change history for a maximum of eight backups.



• The size of the file is calculated by the following formula:

Size of the Block Change Tracking File =

( ( (Threads*2) + number of old backups ) * database size in bytes ) / 250,000



• The minimum size for the block change tracking file is 10 MB.

• By using this formula, a 2 TB database with only one thread, and having five backups in the RMAN repository will require a block change tracking file of 59 MB.



• 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 block change tracking;



• Disabling Block Change TrackingSQL> alter database disable block change 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


Automated Disk-Based Backup and Recovery

• Prior to Oracle 10g, disk files that were created by RMAN utility or ARCH process had no knowledge of one another.

• Furthermore, they were not aware of the sizes of the file system on which they created files. Database administrators need to routinely clean up the old archive logs or old RMAN files.

• It is nice to have a unified disk storage location where you can manage all recovery related files. Now you can achieve this in Oracle 10g by specifying a Recovery Area



• The recovery area is a unified disk storage location 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



• The recovery area is defined by setting two initialization parameters. These two parameters can be dynamically altered or disabled.– The db_recovery_file_dest_size sets the disk

limit, expressed in bytes– The db_recovery_file_dest sets the location

for the recovery area



• Set the disk limit for recovery area to 100 GB: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/’;



• Alter a Recovery Area

SQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE = 200G;

• Disabling a Recovery Area

SQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST = ‘ ’;



• 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.



• 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 parameter specifies 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 for other files.



• New RMAN command for Recovery Area

RMAN> BACKUP RECOVERY AREA;

RMAN> BACKUP RECOVERY FILES;



• 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 NUMBER

NUMBER_OF_FILES NUMBER



• 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 Deregistration

• In Oracle 10g, you can drop a database and remove its entry from the RMAN catalog.

• The following statement drops the entire database 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 archive log files:RMAN> drop database including backups;


RMAN Database Dropping and Deregistration

• The above two statements drop the database 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;


Summary - RMAN Features

• Automated File Creation During Recovery

• Simplified Recovery Through Resetlogs• Change-Aware Incremental Backups• Automated Disk-Based Backup and

Recovery• RMAN Database Dropping and

Deregistration


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


Questions Questions & &

AnswersAnswers


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.


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 winter conference nocoug 2005 winter conference oracle 10g backup and recovery new...

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