Oracle Dba Discussion Board

[KOTC]

[quote name='Joey_Tribbiani' timestamp='1364244567' post='1303485969']
Can we change User passwords when DB is just mounted / not opened ?
[/quote]
No


SQL> alter user dbsnmp identified by forgotten;
alter user dbsnmp identified by forgotten
*
ERROR at line 1:
ORA-01109: database not open

no you can't change

[Joey_Tribbiani]

[quote name='STFU' timestamp='1364254692' post='1303486875']
No


SQL> alter user dbsnmp identified by oracle;
alter user dbsnmp identified by forgotten
*
ERROR at line 1:
ORA-01109: database not open

no you can't change
[/quote]

[KOTC]

[size=4][color=#000000][font=Arial][b] Enable block change tracking[/b][/font][/color]


[color=#000000][b]BLOCK CHANGE TRACKING[/b]
From version 10.2 onwards, Oracle have provided a new tool which is very useful to reduce the time of RMAN incremental backups.
Prior to 10.2, all incremental backups had to read every single block in the database, and if the block has changed, it was backed up. This meant the RMAN backup job took nearly as long as a normal full backup because every block had to be read regardless.
To avoid this, Oracle introduced the BLOCK CHANGE TRACKING file – if this was enabled, then a file called the block change tracking file kept information of all changes to blocks since the last backup. This file was read instead of all the blocks in the database to arrive at changed blocks and then these blocks were backed up.
This reduced the backup time considerably – sometimes, especially in the case of Data Warehouse type databases, since changes happened infrequently, incremental backups hardly took minutes to complete as opposed to many hours.
To enable block change tracking – this can be run with the database open ( as sysdba ).
alter database enable block change tracking using file ‘/hqlinux01db05/ORACLE/test/block_change.dbf’;
Database altered.
select filename,status from v$block_change_tracking;
FILENAME
——————————————————————————–
STATUS
———-
/hqlinux01db05/ORACLE/test/block_change.dbf
ENABLED[/color][/size]

[Gachibowli_Diwakar]

[quote name='STFU' timestamp='1364486367' post='1303502307']
[color=#000000][font=Arial][b] Enable block change tracking[/b][/font][/color]


[color=#000000][b]BLOCK CHANGE TRACKING[/b]
From version 10.2 onwards, Oracle have provided a new tool which is very useful to reduce the time of RMAN incremental backups.
Prior to 10.2, all incremental backups had to read every single block in the database, and if the block has changed, it was backed up. This meant the RMAN backup job took nearly as long as a normal full backup because every block had to be read regardless.
To avoid this, Oracle introduced the BLOCK CHANGE TRACKING file – if this was enabled, then a file called the block change tracking file kept information of all changes to blocks since the last backup. This file was read instead of all the blocks in the database to arrive at changed blocks and then these blocks were backed up.
This reduced the backup time considerably – sometimes, especially in the case of Data Warehouse type databases, since changes happened infrequently, incremental backups hardly took minutes to complete as opposed to many hours.
To enable block change tracking – this can be run with the database open ( as sysdba ).
alter database enable block change tracking using file ‘/hqlinux01db05/ORACLE/test/block_change.dbf’;
Database altered.
select filename,status from v$block_change_tracking;
FILENAME
——————————————————————————–
STATUS
———-
/hqlinux01db05/ORACLE/test/block_change.dbf
ENABLED[/color]
[/quote] database failover aithe due to hardware failure .. make sure you create block_change_tracking data-file in the file-system(usually in datafile filesystem) that swings during the failover scenario.. if not db failover ayyaaka if this file goes missing, db will not be opened
also, when you migrate the db, make sure you also copy this file

[KOTC]

[quote name='Silence..Please' timestamp='1364487642' post='1303502503']
database failover aithe due to hardware failure .. make sure you create block_change_tracking data-file in the file-system(usually in datafile filesystem) that swings during the failover scenario.. if not db failover ayyaaka if this file goes missing, db will not be opened
also, when you migrate the db, make sure you also copy this file
[/quote]


Thanks for the info nuv data guard point of view lo cheptunava??

[Gachibowli_Diwakar]

[quote name='STFU' timestamp='1364488595' post='1303502661']
Thanks for the info nuv data guard point of view lo cheptunava??
[/quote] nope .. hard-ware failover .. i mean cluster failover (like veritas cluster failover) configure chestharu kadha system-admins ..like server panic aina .. server crash aina.. db can come-up on another machine

[KOTC]

[quote name='Silence..Please' timestamp='1364488967' post='1303502726']
nope .. hard-ware failover .. i mean cluster failover (like veritas cluster failover) configure chestharu kadha system-admins ..like server panic aina .. server crash aina.. db can come-up on another machine
[/quote]

ohk ASM use chesinapudu ilanto scenario undavu kadha ??

[Gachibowli_Diwakar]

[quote name='STFU' timestamp='1364489351' post='1303502799']

ohk ASM use chesinapudu ilanto scenario undavu kadha ??
[/quote] e command ichetapudu .. pay gud attention .. and make sure you give ASM DISK Group
[color=#000000][font=helvetica, arial, sans-serif][size=3][background=rgb(247, 247, 247)]alter database enable block change tracking using file ‘/hqlinux01db05/ORACLE/test/block_change.dbf’;[/background][/size][/font][/color]

[KOTC]

[quote name='Silence..Please' timestamp='1364490292' post='1303502970']
e command ichetapudu .. pay gud attention .. and make sure you give ASM DISK Group
[color=#000000][font=helvetica, arial, sans-serif][size=3][background=rgb(247, 247, 247)]alter database enable block change tracking using file ‘/hqlinux01db05/ORACLE/test/block_change.dbf’;[/background][/size][/font][/color]
[/quote]


Thanks bhayya for the info.dani badhulu tracking on cheyaka pothe better emo.

[Gachibowli_Diwakar]

[quote name='STFU' timestamp='1364490439' post='1303503001']


Thanks bhayya for the info.dani badhulu tracking on cheyaka pothe better emo.
[/quote] differential/cumulative backup ki chaala use authundi.. when u enable block-change-tracking

go through this documentation .. u will have a very gud idea (section
[b] 4.4.4 [url=""][/url]Improving Incremental Backup Performance: Change Tracking )[/b]

http://docs.oracle.com/cd/B19306_01/backup.102/b14192/bkup004.htm

[KOTC]

[quote name='Silence..Please' timestamp='1364491345' post='1303503130']
differential/cumulative backup ki chaala use authundi.. when u enable block-change-tracking

go through this documentation .. u will have a very gud idea (section
[b] 4.4.4 Improving Incremental Backup Performance: Change Tracking )[/b]

[url="http://docs.oracle.com/cd/B19306_01/backup.102/b14192/bkup004.htm"]http://docs.oracle.c...192/bkup004.htm[/url]
[/quote]


keka bhayya nuvvu kathi info..

level 0 inka full database backup same kadhu anta.

if we backup level 0 and have level 1's we can restore database without archivelogs until the last level 1 backup done.
ex:sunday level 0 tesukoni,mon,tue,wed level 1 tesukunte wed level 1 travata wed night point of time recovery ki restore cheyachu.
ade full backup undi level 1 unte +archive logs(archive log compulsory) kuda undali anta

backup incremental level 0--idi level 0 ani
backup database----idi full database ani

list backup of database summary;
level dagara F unte---full database
0--unte level 0
1--unte level 1

[KOTC]

Oracle RAC services evaru ayina create chesara??

srvctl config service -d dbname -s servicename

travtha management policy,Failover method,Runtime load balancing set cheyala leka tnsnames.ora pedite saripotundha??

[peru_edaite_enti]

[quote name='Silence..Please' timestamp='1364487642' post='1303502503']
database failover aithe due to hardware failure .. make sure you create block_change_tracking data-file in the file-system(usually in datafile filesystem) that swings during the failover scenario.. if not db failover ayyaaka if this file goes missing, db will not be opened
also, when you migrate the db, make sure you also copy this file
[/quote]

BLOCK CHANGE TRACKING valla performance/throughput cons/degrade emanna untaya??

[KOTC]

[quote name='CBZ' timestamp='1364841693' post='1303522644']
BLOCK CHANGE TRACKING valla performance/throughput cons/degrade emanna untaya??
[/quote]


[size=4][url="http://docs.oracle.com/cd/B19306_01/backup.102/b14192/bkup004.htm"]http://docs.oracle.c...192/bkup004.htm[/url]


[b] 4.4.4 Improving Incremental Backup Performance: Change Tracking[/b]


[font=Tahoma, sans-serif]Change tracking is disabled by default, because it does introduce some [b]minimal performance overhead on your database during normal operations[/b]. However, the benefits of avoiding full datafile scans during backup are considerable, especially if only a small percentage of data blocks are changed between backups. If your backup strategy involves incremental backups, then you should enable change tracking.[/font][/size]

[KOTC]

[quote name='CBZ' timestamp='1364841693' post='1303522644']
BLOCK CHANGE TRACKING valla performance/throughput cons/degrade emanna untaya??
[/quote]


A services create chesava ??