Ausoug2008 Ha Final

7/27/2019 Ausoug2008 Ha Final

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Oracle 11gtaking High Availabil i ty to

the next level

Gavin Soorma

Senior Oracle DBA,

HBOS Australia


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An HA Wish List .

Recover Faster from media failure reduce unplanned downtime

Reduce the cost of inevitable human error

Reduce storage and network bandwidth associated with backups

Reduce the risk and cost associated with change

Perform as many tasks as possible online without planned

outages

Ensure application stability for end users

And .save $$$$ for the business


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What can Oracle 11g deliver?

Reduced backup durations compressed backups, incrementalbackups from Standby database

Reduced recovery durations Data Recovery Advisor

Proactive automatic database health monitoring Increased application availability through efficient SQL plan

stability and optimizer plan management

Real time testing with production data reduced cost as well asrisk of deploying change

Enhanced online application maintenance Flashback Transaction enhancements

and more ..


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Snapshot Standby

Updateable standby database created from Physical Standby

Physical Standby >> Snapshot Standby >> Test >>Physical

Standby

Snapshot Standby is open in read-write mode

Redo received from Primary but not applied

After converting back to Physical Standby, resynchronized with

Primary by applying accumulated redo data

Testing with real time production data on a ready made real timeenvironment

No need to perform production clones


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Snapshot Standby

DGMGRL> show configuration

Configuration

Name: gavinEnabled: YES

Protection Mode: MaxAvailability

Databases:

apex - Primary databaseapexdg - Physical standby database

Fast-Start Failover: DISABLED

Current status for "gavin":

SUCCESS


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Snapshot Standby

DGMGRL> convert database 'apexdg' to snapshot standby;Converting database "apexdg" to a Snapshot Standby database, please

wait...

Database "apexdg" converted successfully

DGMGRL> show configuration

Configuration

Name: gavin

Enabled: YES

Protection Mode: MaxAvailability

Databases:

apex - Primary database

apexdg - Snapshot standby database

Fast-Start Failover: DISABLED

Current status for "gavin":

SUCCESS


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Snapshot Standby

apexdg:/u01/oracle/scripts> export ORACLE_SID=apex

apex:/u01/oracle/scripts> sqlplus sh/SH

SQL*Plus: Release 11.1.0.6.0 - Production on Fri Sep 19 09:40:55 2008

Copyright (c) 1982, 2007, Oracle. All rights reserved.

Connected to:

Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - 64bit Production

With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> create table test_redo_apply

2 as select * from all_objects;

Table created.

SQL> select count(*) from test_redo_apply;

COUNT(*)

----------

56467


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Snapshot Standby

apex:/u01/oracle/scripts> export ORACLE_SID=apexdgapexdg:/u01/oracle/scripts> sqlplus sh/SH



Connected to:



SQL> create table test_snapshot2 as select * from all_objects;

Table created.

SQL> select count(*) from test_snapshot;

COUNT(*)

----------

56467


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Snapshot Standby

DGMGRL> convert database 'apexdg' to physical standby;

Converting database "apexdg" to a Physical Standby database, please wait...

Operation requires shutdown of instance "apexdg" on database "apexdg"

Shutting down instance "apexdg"...

Database closed.

Database dismounted.

ORACLE instance shut down.

Operation requires startup of instance "apexdg" on database "apexdg"

Starting instance "apexdg"...

ORACLE instance started.

Database mounted.

Continuing to convert database "apexdg" ...

Operation requires shutdown of instance "apexdg" on database "apexdg"

Shutting down instance "apexdg"...

ORA-01109: database not open

Database dismounted.

ORACLE instance shut down.

Operation requires startup of instance "apexdg" on database "apexdg"

Starting instance "apexdg"...

ORACLE instance started.

Database mounted.

Database "apexdg" converted successfully

DGMGRL>


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Snapshot Standby

apex:/u01/oracle/scripts> sqlplus sh/SH@apex



Connected to:



SQL> select count(*) from test_snapshot;

select count(*) from test_snapshot*

ERROR at line 1:

ORA-00942: table or view does not exist


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Snapshot Standby

apexdg:/u01/oracle/scripts> dgmgrlDGMGRL for IBM/AIX RISC System/6000: Version 11.1.0.6.0 - 64bit

Production


Welcome to DGMGRL, type "help" for information.

DGMGRL> connect sys/oracle

Connected.

DGMGRL> edit database 'apexdg' set state='apply-off';Succeeded.

DGMGRL> exit


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Snapshot Standby

apexdg:/u01/oracle/scripts> sqlplus / as sysdba



Connected to:



SQL> alter database open read only;

Database altered.

SQL> conn sh/SH@apexdgConnected.

SQL> select count(*) from test_redo_apply;

COUNT(*)

----------

56467


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Data Recovery Advisor

Decreases the amount of time required to recover from

failure

Automatically diagnoses data failures and provides alerts

Automatically assesses the extent and impact of the failure

Automatically suggests multiple repair options based on the

environment and the extent of the assessed damage.

Automates the repair process and verifies if the repair was

successful.


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Automatic Health Monitoring

Automatic Health Monitoring proactively detects problems early intheir life-cycle and notifies the DBA of the user impact andrecommended action to take

Proactively checks the health of the database and identifies anyissues before it impacts end usersData Structure Integrity Check

Data Block Integrity Check

Redo Integrity Check

Undo Segment Integrity Check

Dictionary Integrity Check Part of the 11g Support Workbench and can be run in reactive as

well as manual mode


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apex:/u01/oracle/scripts> cd /u02/oradata/apex/

apex:/u02/oradata/apex> rm example01.dbf

apex:/u02/oradata/apex> sqlplus sh/SH@apex


Copyright (c) 1982, 2007, Oracle. All rights reserved.Connected to:



SQL> select count(*) from test_redo_apply;select count(*) from test_redo_apply

*

ERROR at line 1:ORA-01116: error in opening database file 6

ORA-01110: data file 6: '/u02/oradata/apex/example01.dbf'

ORA-27041: unable to open file

IBM AIX RISC System/6000 Error: 2: No such file or directory

Additional information: 3


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apex:/u02/oradata/apex> rman target /

Recovery Manager: Release 11.1.0.6.0 - Production on Fri Sep 19 10:04:442008


connected to target database: APEX (DBID=1312143933)

RMAN> LIST FAILURE;

using target database control file instead of recovery catalog

List of Database Failures

=========================

Failure ID Priority Status Time Detected Summary

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

162 HIGH OPEN 19-SEP-08 One or more non-systemdatafiles are missing


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RMAN>ADVISE FAILURE;

List of Database Failures

=========================

Failure ID Priority Status Time Detected Summary

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

162 HIGH OPEN 19-SEP-08 One or more non-system datafiles are missing

analyzing automatic repair options; this may take some time

allocated channel: ORA_SBT_TAPE_1

channel ORA_SBT_TAPE_1: SID=107 device type=SBT_TAPE

Mandatory Manual Actions

========================

no manual actions available

Optional Manual Actions

=======================1. If file /u02/oradata/apex/example01.dbf was unintentionally renamed or moved, restore it

Automated Repair Options

========================

Option Repair Description

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

1 Restore and recover datafile 6

Strategy: The repair includes complete media recovery with no data loss

Repair script: /u01/oracle/diag/rdbms/apex/apex/hm/reco_1541621723.hm


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RMAN> REPAIR FAILURE PREVIEW;



contents of repair script:

# restore and recover datafile

sql 'alter database datafile 6 offline';

restore datafile 6;

recover datafile 6;

sql 'alter database datafile 6 online


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RMAN> REPAIR FAILURE NOPROMPT;



...

...

sql statement: alter database datafile 6 offline

Starting restore at 19-SEP-08

using channel ORA_SBT_TAPE_1

using channel ORA_DISK_1

channel ORA_SBT_TAPE_1: starting datafile backup set restore

channel ORA_SBT_TAPE_1: specifying datafile(s) to restore from backup set

channel ORA_SBT_TAPE_1: restoring datafile 00006 to /u02/oradata/apex/example01.dbf

channel ORA_SBT_TAPE_1: reading from backup piece 76jqvhr1_1_1

channel ORA_SBT_TAPE_1: piece handle=76jqvhr1_1_1 tag=TAG20080919T090744

channel ORA_SBT_TAPE_1: restored backup piece 1

channel ORA_SBT_TAPE_1: restore complete, elapsed time: 00:01:05

Finished restore at 19-SEP-08

Starting recover at 19-SEP-08

using channel ORA_SBT_TAPE_1

using channel ORA_DISK_1


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starting media recovery

channel ORA_SBT_TAPE_1: starting archived log restore to default destination

channel ORA_SBT_TAPE_1: restoring archived log

archived log thread=1 sequence=59

channel ORA_SBT_TAPE_1: reading from backup piece 77jqvi1r_1_1

channel ORA_SBT_TAPE_1: piece handle=77jqvi1r_1_1 tag=TAG20080919T091123

channel ORA_SBT_TAPE_1: restored backup piece 1

channel ORA_SBT_TAPE_1: restore complete, elapsed time: 00:00:07

archived log file name=/u03/oradata/apex/arch/arch.1_59_664991234.log thread=1 sequence=59



...

...




archived log file name=/u03/oradata/apex/arch/arch.1_73_664991234.log thread=1 sequence=73archived log file name=/u03/oradata/apex/arch/arch.1_74_664991234.log thread=1 sequence=74

media recovery complete, elapsed time: 00:00:07

Finished recover at 19-SEP-08

sql statement: alter database datafile 6 online

repair failure complete

RMAN>


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SQL> SELECT name FROM v$hm_check WHERE internal_check='N';

NAME

-----------------------------------------------------------DB Structure Integrity Check

Data Block Integrity Check

Redo Integrity Check

Transaction Integrity Check

Undo Segment Integrity Check

Dictionary Integrity Check

6 rows selected.


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SQL> select run_id from V$HM_FINDING where TIME_DETECTED like '19-SEP%';

RUN_ID

----------

5988

SQL> select name from v$hm_run where run_id=5988;

NAME

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

HM_RUN_5988

SQL> select name,time_detected,description,damage_description from V$HM_FINDING

2 where run_id=5988;

NAME

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

TIME_DETECTED

---------------------------------------------------------------------------DESCRIPTION

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

DAMAGE_DESCRIPTION

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

Missing datafile

19-SEP-08 10.10.14.474095 AM

Datafile 6: '/u02/oradata/apex/example01.dbf' is missing

Some objects in tablespace EXAMPLE might be unavailable


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RMAN Enhancements

Network-enabled Database Duplication

A clone database on a remote site can now be easily created directly over the networkwith the enhanced DUPLICATE command without existing backups.

Reduces DBA time and effort and eliminates the storage capacity required at the

remote site for the copy.

Optimized Undo backup

Reduced overall backup time and storage by not backing up undo that applies to

transactions that have already been committed.

Fast Incremental Backups on Physical Standby Database

RMAN can use the block change tracking file on Physical Standby database for incremental

backups backups can be easily offloaded to standby sites to conserve primary host

resources


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Network-enabled Database Duplication

DUPLICATE TARGET DATABASE TO dupdb

FROM ACTIVE DATABASEDB_FILE_NAME_CONVERT

'/oracle/oradata/prod/','/scratch/oracle/oradata/dupdb/'SPFILE

PARAMETER_VALUE_CONVERT

'/oracle/oradata/prod/', '/scratch/oracle/oradata/dupdb/'

SET SGA_MAX_SIZE '300M'

SET SGA_TARGET '250M'

SET LOG_FILE_NAME_CONVERT

'/oracle/oradata/prod/redo/','/scratch/oracle/oradata/dupdb/redo/';


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RMAN Enhancements

Creation and Recovery of Long-Term Backups Improved

Long-term backups created with the KEEP option only back up the archive logs neededto make the backup consistent. No further archive log backups are retained.

Multisection Backups - Parallel Backup and Restore for Very Large Files

Improves the performance of backups and restores of very large data files byparallelizing the workload for each file by dividing the data file into sub sections.

Fast Backup Compression

In addition to the Oracle Database 10g backup compression algorithm (BZIP2), RMAN nowsupports the ZLIB algorithm, which offers 40% better performance, with a trade-off of no morethan 20% lower compression ratio, versus BZIP2.


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Online Application Maintenance

DDL with the WAIT Option

DDL commands require exclusive locks on internal structures.

Set via the WAIT option in the DDL_LOCK_TIMEOUT initialization

parameter.

WAIT option gives you more flexibility to define grace periods for such

commands to succeed instead of raising an error right away

Enhanced ADD COLUMN Functionality

Default values of columns are maintained in the data dictionary for

columns specified as NOT NULL.

Adding new columns with DEFAULT values and NOT NULL constraint

no longer requires the default value to be stored in all existing records.

Enables a schema modification in sub-seconds and independent of the

existing data volume, it also consumes no space


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SQL> CREATE TABLE lock_tab (

id NUMBER);

2 3

Table created.

SQL> INSERT INTO lock_tab VALUES (1);

1 row created.

**NOT COMMITED AT THIS STAGE**

SQL>ALTER TABLE lock_tab ADD (

description VARCHAR2(50)

); 2 3

ALTER TABLE lock_tab ADD (*

ERROR at line 1:

ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired


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SQL>ALTER SESSION SET ddl_lock_timeout=30;

Session altered.

SQL>ALTER TABLE lock_tab ADD (

2 description VARCHAR2(50) );

**NO ERROR THIS TIME SESSION WILL WAIT ...**

SQL> commit;

Commit complete.

SQL> ALTER TABLE lock_tab ADD (2 description VARCHAR2(50)

3 );

Table altered.


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crashdb:/u01/oracle> sqlSQL*Plus: Release 10.2.0.3.0 - Production on Thu Oct 2 10:06:53 2008

Copyright (c) 1982, 2006, Oracle. All Rights Reserved.

Connected to:


With the Partitioning and Data Mining options

SQL> create table myobjects

2 as select * from dba_objects;

Table created.

SQL> select count(*) from myobjects;

COUNT(*)

----------

101580

SQL> set timing on

SQL> alter table myobjects

2 add (new_column varchar2(3) default 'YES' not null);

Table altered.

Elapsed: 00:00:31.68


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apex:/u01/oracle> sql

SQL*Plus: Release 11.1.0.6.0 - Production on Thu Oct 2 10:14:09 2008


Connected to:



SQL> select count(*) from myobjects;

COUNT(*)

----------

142676

SQL> set timing on

SQL> alter table myobjects

2 add (new_column varchar2(3) default 'YES' not null);

Table altered.

Elapsed: 00:00:00.93


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Fine Grained Dependency Management

Finer Grained Dependencies

Pre11g, metadata recorded mutual dependencies between objects with the

granularity of the whole object

This means that dependent objects were sometimes invalidated when there

was no logical requirement to do so.

View V1 depends on Table T1 Columns C1 and C2. if Column c3 is added,

V1 will get invalidated.

Oracle Database 11g records dependency metatdata at a finer level of

granularity reducing the consequential invalidation of dependent objects in

response to changes in the objects they depend upon

Results in increased application availability


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crashdb:/u01/oracle> sql


Copyright (c) 1982, 2006, Oracle. All Rights Reserved.

Connected to:


With the Partitioning and Data Mining options

SQL> create table test_dependency

2 (col_a varchar2(10), col_b varchar2(10));

Table created.

SQL> create view test_dependency_vw

2 as select col_a from test_dependency;

View created.

SQL> alter table test_dependency add (col_c varchar2(10));

Table altered.

SQL> select status from user_objects where object_name='TEST_DEPENDENCY_VW';

STATUS

-------

INVALID


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apex:/u01/oracle/scripts> sql



Connected to:



SQL> create table test_dependency

2 (col_a varchar2(10), col_b varchar2(10));

Table created.

SQL> create view test_dependency_vw

2 as select col_a from test_dependency;

View created.

SQL> alter table test_dependency add (col_c varchar2(10));

Table altered.

SQL> select status from user_objects where object_name='TEST_DEPENDENCY_VW';

STATUS

-------

VALID


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Flashback Enhancements

Block Recovery can now be performed from the Flashback Logs on disk.

Reduces recovery time by potentially eliminating time consuming

restores from tape to repair a few corrupt blocks.

Information Life Cycle management using Flashback Data Archives

Guaranteed retention of historical and archived data

No need to rely on UNDO tablespace data retention policies

Flashback Data archive stored in a tablespace and contains

transactional changes to every record in a table

Flashback Transaction can easily back out a transaction and itsdependent transactions.

DBMS_FLASHBACK.TRANSACTION_BACKOUT() procedure rolls back

a transaction and its dependent transactions while the database remains

online.


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Flashback Transaction - Backout

SQL> INSERT INTO hr.regions VALUES (10,'Pole');

1 row created.

SQL> INSERT INTO hr.regions VALUES (20,'Moon');

1 row created.

SQL> commit;

Commit complete.

SQL> UPDATE hr.regions SET region_name='Two Poles' WHERE region_id = 10;

1 row updated.

SQL> UPDATE hr.regions SET region_name='Two Moons' WHERE region_id=20;

1 row updated.

SQL> commit;

Commit complete.


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SQL> UPDATE hr.regions SET region_name='Three Poles' WHERE region_id = 10;

1 row updated.

SQL> UPDATE hr.regions SET region_name='Three Moons' WHERE region_id=20;

1 row updated.

SQL> commit;

Commit complete.

SQL> select * from regions;

REGION_ID REGION_NAME

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

1 Europe

2 Americas3 Asia

4 Middle East and Africa

10 Three Poles

20 Three Moons

6 rows selected.


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SQL> select xid,operation from flashback_transaction_query

2 where table_name='REGIONS'

3 and trunc(start_timestamp)='02-OCT-2008';

XID OPERATION

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

0009001B000024EE INSERT

000A000200001C9F UPDATE

000A000200001C9F UPDATE

SQL> BEGIN

DBMS_FLASHBACK.transaction_backout (numtxns => 1,

xids => xid_array('0009001B000024EE'),

options => DBMS_FLASHBACK.nocascade);

END;

/ 2 3 4 5 6

BEGIN

*ERROR at line 1:

ORA-55504: Transaction conflicts in NOCASCADE mode

ORA-06512: at "SYS.DBMS_FLASHBACK", line 37

ORA-06512: at "SYS.DBMS_FLASHBACK", line 70

ORA-06512: at line 2


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SQL> BEGIN

DBMS_FLASHBACK.transaction_backout (numtxns => 1,

xids => xid_array('0009001B000024EE'),

options => DBMS_FLASHBACK.cascade);

end;

/

PL/SQL procedure successfully completed.

SQL> select COMPENSATING_XID,DEPENDENT_XID,BACKOUT_MODE

2 FROM dba_flashback_txn_state

3 WHERE xid = '0009001B000024EE';

COMPENSATING_XID DEPENDENT_XID BACKOUT_MODE

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

000A000200001CA2 0004001D00001D21 CASCADE

SQL> select * from hr.regions;

REGION_ID REGION_NAME

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

1 Europe

2 Americas

3 Asia

4 Middle East and Africa


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Flashback Data Archive Total Recall

SQL> create tablespace archive_data

2 datafile '/u02/oradata/apex/archive_data01.dbf' size 1024m;

Tablespace created.

SQL> create flashback archive year1 tablespace archive_data

2 quota 500m retention 1 year;

Flashback archive created.

SQL> grant flashback archive on year1 to HR;

Grant succeeded.

SQL> conn HR/HRConnected.

SQL> alter table regions flashback archive year1;

Table altered.


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Flashback Data Archive Total Recall

SQL> conn / as sysdba

Connected.

SQL> SELECT table_name, owner_name, flashback_archive_name, archive_table_name

FROM dba_flashback_archive_tables;

TABLE_NAME OWNER_NAME FLASHBACK_ARCHIVE_NA ARCHIVE_TABLE_NAME--------------- --------------- -------------------- --------------------

REGIONS HR YEAR1 SYS_FBA_HIST_79593

SQL> SELECT flashback_archive_name, retention_in_days

FROM dba_flashback_archive;

FLASHBACK_ARCHIVE_NA RETENTION_IN_DAYS

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

YEAR1 365


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SQL Plan Management

Overcomes limitations with Stored Outlines (8i) and SQL Profiles

(10g)

Guarantees plan stability by ensuring only accepted execution plans

are ever used by the CBO Once plans are accepted and evolved, all subsequent executions of

the same SQL statement will always use that plan unless a new plan

with a lower cost is made available by the CBO

SMB SQL Management Base stores SQL text, its outline, bind

variables in SYSAUX tablespace.

OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES

OPTIMIZER_USE_SQL_PLAN_BASELINES


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Gathering and Publishing Statistics

Pre 11g,the statistics were automatically published once the gather was

completed.

New statistics can invalidate plans and can result in new (inefficient)execution paths.

In 11g test the statistics before publishing them and ensure only

acceptable plans are used by the Optimizer

Gather Statistics >> Pending Statistics >> Published Statistics

Ensure plan stability and increased application availability


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ASM Fast Mirror Resync

Pre 11g, temporary transient failures (cable disconnect) will cause disk to be

dropped from disk group straight away.

ASM would rebalance the disk group after dropping the disk rebalance

again after adding disk once problem is rectified

Rebalancing operations increases I/O significantly.

ASM attribute disk_repair_time now provides a window for repair disk is

dropped if this window expires default 3.6 hours

After disk is online, only extents that have been marked as modified

need to be rebalanced after failed disk joins disk group.

Once the disk is available, only the changed extents are written to

resynchronize the disk, rather than overwriting the contents of the entire disk

ALTER DISKGROUP dgroupA SET ATTRIBUTE DISK_REPAIR_TIME=3H;


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ASM Metadata Backup and Restore

Pre Oracle 11g no backup of ASM meta data

If disk group is lost, restore lost files via RMAN, but manually

recreate ASM disk group as well as user directories/templates

11g ASMCMD includes ASM metadata backup and restore

Parses ASM fixed tables and views to get information on disk and

failure group configuration, templates and alias directory structure

ASMCMD> md_backupb asm_metadata

g data

ASMCMD> md_restore b asm_metadata t full g data


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Miscellaneous

Online Patching

ASM Rolling Upgrade from 10g R2 to 11g

Online redefinition of tables with MVs and MV Logs

ADRCI and Incident Packaging Service

Rebuild indexes online without any exclusive lock at the

beginning and end of the operation

SQL Repair Advisor repair SQL statements causing ORA-600s

by providing a customised SQL patch after recompiling and re-executing SQL statement


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Thanks for attending!!

Q U E S T I O N S

A N S W E R S

GAVIN SOORMA

Senior Oracle DBA Specialist

HBOS Australia

Contact me at : 0417713124

[email protected]

Ausoug2008 Ha Final

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