Thursday, September 22, 2011

SMON - How it will handle instance recovery

Instance recovery occurs in two steps:
1.Cache Recovery
2.Transaction Recovery
Cache recovery:
Changes being made to a database are recorded in the database buffer cache. These changes are also recorded in online redo log files simultaneously.
When there are enough data in the database buffer cache, they are written to data files.
If an Oracle instance fails before the data in the database buffer cache are written to data files, Oracle uses the data recorded in the online redo log files to recover the lost data when the associated database is re-started. This process is called cache recovery.

Transaction recovery:
When a transaction modifies data in a database, the before image of the modified data is stored in an undo segment.The data stored in the undo segment is used to restore the original values in case a transaction is rolled back. At the time of an instance failure, the database may have uncommitted transactions. It is possible that changes made by these uncommitted transactions have gotten saved in data files.(We don't have any mechanism to track this)
To maintain read consistency, Oracle rolls back all uncommitted transactions when the associated database is re-started. Oracle uses the undo data stored in undo segments to accomplish this. This process is called transaction recovery.

ORA-01565

ORA-01565: error in identifying file /dbs/spfile@.ora
When we’re going to create pfile from spfile while spfile running on ASM instance, We can face the below errors,
SQL> create pfile=’/u01/inittest.ora’ from spfile;
create pfile=’/u01/inittest.ora’ from spfile
*
ERROR at line 1:
ORA-01565: error in identifying file ‘?/dbs/spfile@.ora’
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3

Solution :
We need to give ASM path of SPFILE.
SQL> create pfile=’/u01/inittest.ora’ from spfile=’+DATA/dbasm/spfiledbasm.ora’;
File created.

ORA-01031

Could not validate asmsnmp password due to following error ora-01031:insufficent privileges
[oracle@db1 ~]$ export ORACLE_HOME=/u01/app/oracle/product/11.2.0/grid
[oracle@db1 ~]$ export PATH=/u01/app/oracle/product/11.2.0/grid/bin
[oracle@db1 ~]$ export ORACLE_SID=+ASM
[oracle@db1 ~]$ sqlplus sys/sys as sysasm
SQL> create user asmsnmp identified by asmsnmp;
User created.
SQL> grant sysdba to asmsnmp;
Grant succeeded.

Encryption for RMAN Backup

RAM backups are unencrypted.

we can encrypt any rman backup in the form of a backup set.

we can encrypt in two ways ie transport and password encryption

Password Encryption:


$export ORACLE_SID=TEMP

$rlwrap rman target sys/oracle

rman>set encryption on identified only;


Here i am choosing encryption on tablespace ie users

rman>configure encryption for tablespace users on;

rman>sql'alter tablespace users offline';

rman>restore tablespace users;

failed we need to

Rman>set decryption identified by ;

Rman>restore tablespace users;

rman> recover tablespace users;

rman>sql'alter tablespace users online';

Wednesday, September 21, 2011

Duplicate Database Using RMAN

You want to use RMAN to create a duplicate database on the same server by using RMAN backups.

My Source Database Name is MYTEST

Target (duplicate) Database name is MYDB

Step 1: Configure Listener.ora and tnsnames.ora files

tnsnames.ora file

MYTEST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = mytest)
)
)

MYDB =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = mydb)
)
)

listener.ora file

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = mytest)
(ORACLE_HOME = /home/oracle/oracle/product/10.2.0/db_1)
(SID_NAME = mytest)
)
(SID_DESC =
(GLOBAL_DBNAME= mydb)
(ORACLE_HOME = /home/oracle/oracle/product/10.2.0/db_1)
(SID_NAME = mydb)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain)(PORT = 1521))
)
)

Step 2: create pfile for target database from source database

SQL> create pfile from spfile;

File created.

Step 3: modified parameter file for target database (duplicate) here log_file_name_convert and db_file_name_convert and control file location is important, further your choice.

*.audit_file_dest=’/home/oracle/oracle/product/10.2.0/db_1/admin/mydb/adump’
*.compatible=’10.2.0.1.0′
*.db_block_size=8192
*.db_domain=”
*.db_file_multiblock_read_count=16
*.db_name=’mydb’
*.control_files=’/home/oracle/oracle/product/10.2.0/oradata/mydb/control01.ctl’,'/home/oracle/oracle/product/10.2.0/oradata/mydb/control02.ctl’,'/home/oracle/oracle/product/10.2.0/oradata/mydb/control03.ctl’
*.db_file_name_convert=’/home/oracle/oracle/product/10.2.0/db_1/oradata/mytest’,'/home/oracle/oracle/product/10.2.0/oradata/mydb’
*.log_file_name_convert=’/home/oracle/oracle/product/10.2.0/db_1/oradata/mytest’,'/home/oracle/oracle/product/10.2.0/oradata/mydb’
*.db_recovery_file_dest=’/home/oracle/oracle/product/10.2.0/db_1/flash_recovery_area’
*.db_recovery_file_dest_size=2147483648
*.dispatchers=’(PROTOCOL=TCP) (SERVICE=mydbXDB)’
*.job_queue_processes=10
*.open_cursors=300
*.pga_aggregate_target=94371840
*.processes=150
*.remote_login_passwordfile=’EXCLUSIVE’
*.sga_target=285212672
*.undo_management=’AUTO’
*.undo_tablespace=’UNDOTBS1′

Step 4: Create password file

[oracle@localhost ~]$orapwd file=orapwmydb password=oracle entries=5

Step 5: start your target database nomount stage

[oracle@localhost ~]$ export ORACLE_SID=mydb
[oracle@localhost ~]$ rlwrap sqlplus

SQL*Plus: Release 10.2.0.1.0 – Production on Tue May 25 18:22:09 2010

Copyright (c) 1982, 2005, Oracle. All rights reserved.

Enter user-name: sys/oracle@mydb as sysdba

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 – Production
With the Partitioning, OLAP and Data Mining options

SQL> startup nomount pfile=/home/oracle/oracle/product/10.2.0/db_1/dbs/initmydb.ora
ORACLE instance started.

Total System Global Area 285212672 bytes
Fixed Size 1218992 bytes
Variable Size 92276304 bytes
Database Buffers 188743680 bytes
Redo Buffers 2973696 bytes
SQL> exit

Step 6: From source database

SQL> alter system switch logfile;

System altered.

SQL>

Step 7: Backup database and archivelog Source database

[oracle@localhost root]$ rlwrap rman target sys/azar@mytest

Recovery Manager: Release 10.2.0.1.0 – Production on Tue May 25 19:56:10 2010

Copyright (c) 1982, 2005, Oracle. All rights reserved.

connected to target database: MYTEST (DBID=2419076664)

RMAN> backup database plus archivelog;

Starting backup at 25-MAY-10
current log archived

input datafile fno=00001 name=/home/oracle/oracle/product/10.2.0/db_1/oradata/mytest/system01.dbf
input datafile fno=00003 name=/home/oracle/oracle/product/10.2.0/db_1/oradata/mytest/sysaux01.dbf
input datafile fno=00002 name=/home/oracle/oracle/product/10.2.0/db_1/oradata/mytest/undotbs01.dbf
input datafile fno=00004 name=/home/oracle/oracle/product/10.2.0/db_1/oradata/mytest/users01.dbf
channel ORA_DISK_1: starting piece 1 at 25-MAY-10
channel ORA_DISK_1: finished piece 1 at 25-MAY-10

(skipped)

Starting Control File and SPFILE Autobackup at 25-MAY-10
piece handle=/home/oracle/oracle/product/10.2.0/db_1/flash_recovery_area/MYTEST/autobackup/2010_05_25/o1_mf_s_719956316_5zr01f85_.bkp comment=NONE
Finished Control File and SPFILE Autobackup at 25-MAY-10

Step 8: Connect auxiliary database

RMAN> connect auxiliary sys/oracle@mydb;

connected to auxiliary database: MYDB (not mounted)

Step 9: Create duplicate database.

RMAN> duplicate target database to mydb;

Starting Duplicate Db at 25-MAY-10
using target database control file instead of recovery catalog
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: sid=156 devtype=DISK

contents of Memory Script:
{
set until scn 470310;
set newname for datafile 1 to
“/home/oracle/oracle/product/10.2.0/oradata/mydb/system01.dbf”;
set newname for datafile 2 to
“/home/oracle/oracle/product/10.2.0/oradata/mydb/undotbs01.dbf”;
set newname for datafile 3 to
“/home/oracle/oracle/product/10.2.0/oradata/mydb/sysaux01.dbf”;
set newname for datafile 4 to
“/home/oracle/oracle/product/10.2.0/oradata/mydb/users01.dbf”;
restore
check readonly
clone database
;
}
executing Memory Script

executing command: SET until clause

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

executing command: SET NEWNAME

Starting restore at 25-MAY-10
using channel ORA_AUX_DISK_1

skipping datafile 1; already restored to file /home/oracle/oracle/product/10.2.0/oradata/mydb/system01.dbf
skipping datafile 2; already restored to file /home/oracle/oracle/product/10.2.0/oradata/mydb/undotbs01.dbf
skipping datafile 3; already restored to file /home/oracle/oracle/product/10.2.0/oradata/mydb/sysaux01.dbf
skipping datafile 4; already restored to file /home/oracle/oracle/product/10.2.0/oradata/mydb/users01.dbf
restore not done; all files readonly, offline, or already restored
Finished restore at 25-MAY-10
sql statement: CREATE CONTROLFILE REUSE SET DATABASE “MYDB” RESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 ( ‘/home/oracle/oracle/product/10.2.0/oradata/mydb/redo01.log’ ) SIZE 50 M REUSE,
GROUP 2 ( ‘/home/oracle/oracle/product/10.2.0/oradata/mydb/redo02.log’ ) SIZE 50 M REUSE,
GROUP 3 ( ‘/home/oracle/oracle/product/10.2.0/oradata/mydb/redo03.log’ ) SIZE 50 M REUSE
DATAFILE
‘/home/oracle/oracle/product/10.2.0/oradata/mydb/system01.dbf’
CHARACTER SET WE8ISO8859P1

contents of Memory Script:
{
switch clone datafile all;
}
executing Memory Script

released channel: ORA_AUX_DISK_1
datafile 2 switched to datafile copy
input datafile copy recid=1 stamp=719956582 filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/undotbs01.dbf
datafile 3 switched to datafile copy
input datafile copy recid=2 stamp=719956582 filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/sysaux01.dbf
datafile 4 switched to datafile copy
input datafile copy recid=3 stamp=719956582 filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/users01.dbf

contents of Memory Script:
{
set until scn 470310;
recover
clone database
delete archivelog
;
}
executing Memory Script

executing command: SET until clause

Starting recover at 25-MAY-10
allocated channel: ORA_AUX_DISK_1
channel ORA_AUX_DISK_1: sid=156 devtype=DISK

starting media recovery

archive log thread 1 sequence 9 is already on disk as file /home/oracle/oracle/product/10.2.0/db_1/flash_recovery_area/MYTEST/archivelog/2010_05_25/o1_mf_1_9_5zr01bl8_.arc
archive log filename=/home/oracle/oracle/product/10.2.0/db_1/flash_recovery_area/MYTEST/archivelog/2010_05_25/o1_mf_1_9_5zr01bl8_.arc thread=1 sequence=9
media recovery complete, elapsed time: 00:00:02
Finished recover at 25-MAY-10

contents of Memory Script:
{
shutdown clone;
startup clone nomount ;
}
executing Memory Script

database dismounted
Oracle instance shut down

connected to auxiliary database (not started)
Oracle instance started

Total System Global Area 285212672 bytes

Fixed Size 1218992 bytes
Variable Size 92276304 bytes
Database Buffers 188743680 bytes
Redo Buffers 2973696 bytes
sql statement: CREATE CONTROLFILE REUSE SET DATABASE “MYDB” RESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 ( ‘/home/oracle/oracle/product/10.2.0/oradata/mydb/redo01.log’ ) SIZE 50 M REUSE,
GROUP 2 ( ‘/home/oracle/oracle/product/10.2.0/oradata/mydb/redo02.log’ ) SIZE 50 M REUSE,
GROUP 3 ( ‘/home/oracle/oracle/product/10.2.0/oradata/mydb/redo03.log’ ) SIZE 50 M REUSE
DATAFILE
‘/home/oracle/oracle/product/10.2.0/oradata/mydb/system01.dbf’
CHARACTER SET WE8ISO8859P1

contents of Memory Script:
{
set newname for tempfile 1 to
“/home/oracle/oracle/product/10.2.0/oradata/mydb/temp01.dbf”;
switch clone tempfile all;
catalog clone datafilecopy “/home/oracle/oracle/product/10.2.0/oradata/mydb/undotbs01.dbf”;
catalog clone datafilecopy “/home/oracle/oracle/product/10.2.0/oradata/mydb/sysaux01.dbf”;
catalog clone datafilecopy “/home/oracle/oracle/product/10.2.0/oradata/mydb/users01.dbf”;
switch clone datafile all;
}
executing Memory Script

executing command: SET NEWNAME

renamed temporary file 1 to /home/oracle/oracle/product/10.2.0/oradata/mydb/temp01.dbf in control file

cataloged datafile copy
datafile copy filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/undotbs01.dbf recid=1 stamp=719956593

cataloged datafile copy
datafile copy filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/sysaux01.dbf recid=2 stamp=719956593

cataloged datafile copy
datafile copy filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/users01.dbf recid=3 stamp=719956593

datafile 2 switched to datafile copy
input datafile copy recid=1 stamp=719956593 filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/undotbs01.dbf
datafile 3 switched to datafile copy
input datafile copy recid=2 stamp=719956593 filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/sysaux01.dbf
datafile 4 switched to datafile copy
input datafile copy recid=3 stamp=719956593 filename=/home/oracle/oracle/product/10.2.0/oradata/mydb/users01.dbf

contents of Memory Script:
{
Alter clone database open resetlogs;
}
executing Memory Script

database opened
Finished Duplicate Db at 25-MAY-10

RMAN>

Step 10: My duplicate database succesfully created.

Enter user-name: sys/oracle@mydb as sysdba

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 – Production
With the Partitioning, OLAP and Data Mining options

SQL> select status from v$instance;

STATUS
————
OPEN

SQL> select name from V$database;

NAME
———
MYDB

SQL>