5BackupRecoveryW

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Backup and Recovery



Backup Types

Logical

Physical

Hot

Cold

Without

With



Issues

– Protect the database from numerous types of failures

– Increase Mean-Time-Between-Failures (MTBF)

– Decrease Mean-Time-To-Recover (MTTR)

– Minimize data loss



Categories of Failures

– Statement failure

– Logic error in an application

– Attempt to enter bad data into the table

–

Attempt an operation with insufficientprivileges

– Attempt an INSERT or UPDATE to a table,

causing an extent to be allocated,

but with insufficient free space

left in the tablespace

No Recovery Needed





– User process failure

– The user performed an abnormal disconnect

in the session.

– The user’s session was abnormally terminated.

–

The user’s program raised an addressexception terminating the session.

No Recovery Needed PMON






– User error

– Accidental DROP TABLE;

– Accidental TRUNCATE TABLE;

– Accidental DELETE / UPDATE;

Recovery Needed

IMP Utility






– User error

– Instance failure

– HardWare Problem on CPU / RAM

No Recovery Needed

PMON SMON






– User error

– Instance failure

– Media failure

– HardWare Problem on I/O Device

Recovery Needed Physical



Requirements for Strategy

– Business requirements

• Evolutionary process

– Technical requirements

• Hardware, software, man power and time

• Database configurations

• Transaction volume

• Frequency of backups

–

Operational requirements• 7-day / 24-hour operations

• Testing and validating backups



Physical Backup Methods

Physical backup

Archivemode

No archivemode



ARCHIVELOG

Archived logfile

052ARC0

LOG_ARCHIVE_DEST

/disk1/archive/

Online redo log files

052

052

Group 2

053

Group 1

053

LOG_ARCHIVE_FORMAT

arch%s.arc



Enabling ARCHIVELOG

Mode

Init.ora Control

file

Shutdown normal or immediate1

Startup mount2

Alter database ARCHIVELOG 3

Alter database open 4

Shutdown normal orimmediate

5

Full database backup6



Physical Closed Database Backup

Passwordfile

Online oroffline

storage

Controlfiles

Parameterfiles

Data files Redo logfiles

SHUTDOWN IMMEDIATE;

STARTUP OPEN;

HOST cp <files> /backup/



Advantages of Physical Closed

Database Backups

– Conceptually simple

– Easy to perform

– Require little operator interaction



Physical Opened Database

Backup (1)

Archived redolog files

Parameterfiles

Pwd file

Onlineredo

log files

Controlfiles

Online oroffline

storage




Data files

Physical Opened Database

Backup (2)

Online oroffline

storage


SQL> alter tablespace <name> begin backup;

SQL> alter tablespace <name> end backup;

All tablespace datafiles

Individual datafile



Advantages of Physical Opened

Database Backups

– Maintains high database availability

– Can be done at a tablespace or data file level

– Supports nonstop business operations



Data files

Redo logfiles

Controlfile

1

1

Archived log file

ARC0

1



Redo logfiles

Controlfile

2

2

Archived log file

1ARC0

1

2

Data files



Redo logfiles

Controlfile

3

3

Archived log file

1ARC0

3

22

Data files



Redo logfiles

Controlfile

4

4

Archived log file

1ARC0

3

42

3

Data files



Redo logfiles

Controlfile

5

5

Archived log file

1ARC0

5

42

3 4

Data files

Data files

5

Control

file

5



Redo logfiles

Controlfile

6

6

Archived log file

1ARC0

5

62

3 4

Data files

Data files

5

Control

file

5

5



Redo logfiles

Controlfile

9

9

Archived log file

1ARC0

9

82

3 4

Data files

Data files

5

Control

file

5

5 6

7 8



Shutdown1

Startup Mount2

O.S. Restore From Hot or Cold Physical BackUp DataFile (s)3

Redo logfiles

Controlfile

9

9

Data files

9

9

85

Recover DataFile (s) Automatic4

Applyed Archived Logs #5 #6 #74a

Applyed On Line Logs #8 #94b

Alter DataBase Open5

9

Shutdown Immediate6

New Cold Physical BackUp7

Startup Open8



S.C.N. System Change Number

Control fileData files

HeaderRedoRecord

Incremental Time Stamp1

Unique Identified “Committed Version D.B.” 2

Log file

Log file #

Low SCN #

Higth SCN #



Oracle Export and Import

Utilities

Logical Backup Methods

• An interactive dialog

• The export page of the Data Manager withinEnterprise Manager

• The command line interface, by specifyingparameters



These utilities enable you to do the following:

– Archive historical data

– Save table definitions (with or without data) to protect

from user error failure – Move data between machines and databases or versions

of the Oracle server

– Transport tablespaces between databases



Data

BaseExp File *.dmp

ImpData

Base

Formato

Binario

Proprietario



Oracle Server

Export Concepts

Generate SQLcommands

Dump file

Two-Taskcommon

(TTC)

Buffercache

SQLcommand

processing

TTCbuffer

Buffercache

manager

Evaluatingbuffer

Analyze blocks

Read blocks

Oracle9i Server

Tables

3Owner

2Full

1IncType Complete1a

IncType Cumulative1b

IncType Incremental1c



KEYWORD DESCRIPTION (DEFAULT)

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

USERID username/password

BUFFER size of data buffer

FILE output files (EXPDAT.DMP)LOG log file of screen output

PARFILE parameter filename

FILESIZE maximum size of each dump file

COMPRESS import into one extent (Y)

CONSISTENT cross-table consistency (N)

GRANTS export grants (Y)

INDEXES export indexes (Y)

ROWS export data rows (Y)

CONSTRAINTS export constraints (Y)

TRIGGERS export triggers (Y)

FULL export entire DataBase (N)

OWNER list of owner usernames

TABLES list of table names

INCTYPE incremental export type

DIRECT direct path (N)

STATISTICS analyze objects (ESTIMATE)



Command-Line Method

> exp scott/tiger file=scott.dmp owner=scott grants=Y rows=Y compress=Y

Export Messages

Export: Release 9.2.0.4.0 - Production on Fri Oct 30 09:35:33 1998(c) Copyright 2003 Oracle Corporation. All rights reserved.Connected to: Oracle9i Enterprise Edition Release 9.2.0.4.0 - ProductionWith the Partitioning option

PL/SQL Release 9.2.0.4.0 - ProductionExport done in WE8DEC character set and WE8DEC NCHAR character set. exporting pre-schema procedural objects and actions. exporting foreign function library names for user SCOTT. exporting object type definitions for user SCOTT About to export SCOTT’s objects ...

. exporting database links

. exporting sequence numbers

. exporting cluster definitions

. about to export SCOTT’s tables via Conventional Path ...

. . exporting table BONUS 0 rows exported

. . exporting table DEPT 4 rows exported

. . exporting table EMP 14 rows exported



IncType Complete

IncType Incremental -----> Exp IncType Generic

IncType Cumulative -----> Exp IncType Cumulative or Complete



Oracle Standby

Implementation

• Fail over Solution

• Disaster Recovery Solution (if remote)

• Ease of implementation

• Minimum impact on Production System• Read Only Standby Database

O i f M d O l St db DB



Overview of Managed Oracle Standby DB

Primary

control file

Primary DB

Primary Instance

Redo log

Arc log

ARCH

Standby DB

DBWR

Standby Instance

Recovery proc

Standby

control file

RFS

Arc log

T.N.S.

Recovery Mode1

ReadOnly Mode2

Activate3

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