Tcoug-rman 11g New Features

8/9/2019 Tcoug-rman 11g New Features

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RMAN 11g:

New Recovery Features

Matt Hart

Twin CitiesApril 2008


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Agenda

Oracle Database 11g: Data Protection

Enhancements

RMAN 11g: Backup enhancements RMAN 11g: Recovery Enhancements


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Oracle Database 11g: Data Protection

Enhancements Advanced Data Corruption Protection

Flashback Improvements


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Advanced Data Corruption Protection

DB_ULTRA_SAFE=(off, data_only, data_and_index)

Controls DB_BLOCK_CHECKING, DB_BLOCK_CHECKSUM, andDB_LOST_WRITE_PROTECT

If DB_ULTRA_SAFE is OFF, but any of these parameters are set, OFFdoes not effect them

When ULTRA_SAFE is set: DATA_ONLY:

DB_BLOCK_CHECKING will be set to MEDIUM.

DB_LOST_WRITE_PROTECT will be set to TYPICAL.

DB_BLOCK_CHECKSUM will be set to FULL.

DATA_AND_INDEX: DB_BLOCK_CHECKING will be set to FULL.

DB_LOST_WRITE_PROTECT will be set to TYPICAL. DB_BLOCK_CHECKSUM will be set to FULL.


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Flashback transaction

Flashback Data Archive


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Flashback Transaction

Requirements:

Archivelog mode ON

Minimal supplemental logging: on

From mount: ALTER DATABASE ADD SUPPLEMENTAL LOG

DATA (PRIMARY KEY) COLUMNS; LOBs are not enabled by this. They must be turned on per

column per table with alter table... retention command

PL/SQL usage:

DBMS_FLASHBACK.TRANSACTION_BACKOUT

numberofxids NUMBER,xids XID_ARRAY,

options NUMBER default NOCASCADE,

timeHint TIMESTAMP default MINTIME);


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Flashback Data Archive

Database capability to turn on tracking for allchanges to a table, stored within a tablespace for aspecified amount of time

Removes requirement to put this into the application

layer Provides auditing and archiving function for

compliance purposes

CREATE FLASHBACK ARCHIVE DEFAULTFLASH01 TABLESPACE FBA QUOTA 10GRETENTION 1 YEAR;

Alter table matt.junk2 flashback archive;


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Flashback Archive: restrictions

DROP TABLE statement

RENAME TABLE statement

TRUNCATE TABLE statement

ALTER TABLE statement that does any of thefollowing: Drops, renames, or modifies a column

Performs partition or subpartition operations

Converts a LONG column to a LOB column

Includes an UPGRADE TABLE clause, with or without anINCLUDING DATA clause


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Flashback Archive Lookup

DBA_FLASHBACK_ARCHIVE for data on

existing archives

DBA_FLASHBACK_ARCHIVE_TABLES for

listing of tables in archives

DBA_FLASHBACK_ARCHIVE_TS for

tablespace data on archives


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RMAN 11g Backup Enhancements

Parallel backup of a single file

Archive Log mgmt improvements

Fast incremental backup on physical standby

Undo-aware backup RMAN Catalog Merge

Other backup enhancements


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Parallel backup of a single file

Prior to 11g, the smallest unit of parallelization inRMAN was the datafile

Multiple channels could work on multiple files, butthat was it

In 11g, the backup SECTION is introduced Now, multiple channels can chunk a file into

smaller units

If a tablespace has only one datafile of size 1GB,

and you want to utilize 4 channels: Allocate 4 disk channels, then: BACKUP SECTION SIZE 250M TABLESPACE junk;


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Archivelog management enhancements

RMAN is Data guard aware

Will not compromise a DG environment during

automatic archivelog backup and cleanout

RMAN is Streams Aware

Will not compromise a Streams environment

during automatic archivelog backup and cleanout

RMAN allows for optional archivelogdestinations if FRA is unavailable during

backup


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Fast Incremental Backups on Standby

Databases Starting with 11g, you can enable block

change tracking on standby database

This allows fast incremental backups against

the standby


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Undo-aware backup

RMAN now avoids undo blocks that are not

required during recovery from that restore

point

Unneeded (committed) undo is not backed up

This can make up the bulk of UNDO, and signify a

massive amount of backup writes (and thus

restore reads)


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RMAN Catalog Merge

RMAN catalogs can be imported into anothercatalog, or easily moved to a new database

IMPORT CATALOG command is used

Connect to the new catalog (or new location) Issue command specifying catalog owner and TNS

connection for exporting location

rmanRMAN> CONNECT CATALOG rman@cat02;

IMPORT CATALOG rman17@cat01;

Can import only certain database sets of metadata:

IMPORT CATALOG rman17@cat01 DB_NAME=test, pmod;


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Other Backup Improvements

Network-aware duplicate

Clones created directly over network without

moving backups to clone location

Read-only transported tablespaces can be

backed up.

Improved backup compression performance


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RMAN 11g Recovery Enhancements

Improved redo apply

Block Media Recovery performance

improvements

Single datafile validation very large files

Data Recovery Advisor


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Improved redo apply performance

Internal improvements in how media recovery

utilizes multiple CPUs during media recovery

has improved media recovery

Do I have benchmarks? Not yet

This allows for real-time DR using standby

databases for higher volume databases

Also reduces overall MTTR based on time toapply archivelogs


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Block Media Recovery performance

improvements In a situation where flashback logs exist (as

part of turning on flashback database), these

can be used to restore a block for BMR

Reduces need to go to physical backup to get

original block prior to applying redo to bring

the block up to current SCN


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Parallel validation on a single file

The SECTION functionality of backup applies

validation as well

VALIDATE DATAFILE 1 SECTION SIZE 1200M;

RMAN does not permit restoring in

SECTIONS

(Recovery is capable of parallelism at the

database instance level)


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Data Recovery Advisor

New database tool that automatically detects

data failures (corruptions or loss of persistent

data)

Offers advice on a resolution plan and can

implement fixes

Provides an early warning system for data

failures, prior to a db process or userencountering the issue


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