This one maybe one of the best RAC setup articles of all times - Oracle 11g RAC on Oracle Enterprise Linux 4(Update 5) and VMware Server
next patchset for Oracle 10gR2
10.2.0.4 should be available this year on Linux x86. Check Metalink Certification for different plateforms.
Certify - Additional Info Oracle Database - Enterprise Edition Version 10gR2 On Linux (x86)
Operating System: Linux (x86) Version SLES-10
Oracle Database - Enterprise Edition Version 10gR2
N/A Version N/A
Status: Certified
Product Version Note:
None available for this product.
Certification Note:
Existing patch sets:
10.2.0.2
10.2.0.3
10.2.0.4 Q4CY2007
Advice on data recovery, parallel backup of the same file, and virtual catalogs for security are just a few of the new gems available from RMAN in Oracle Database 11g.
Data Recovery Advisor
Consider the error shown below:
SQL> conn scott/tiger
Connected.
SQL> create table t (col1 number);
create table t (col1 number)
*
ERROR at line 1:
ORA-01116: error in opening database file 4
ORA-01110: data file 4: '/home/oracle/oradata/PRODB3/users01.dbf'
ORA-27041: unable to open file
Linux Error: 2: No such file or directory
Additional information: 3
Does it look familiar? Regardless of your experience as a DBA, you probably have seen this message more than once. This error occurs because the datafile in question is not available—it could be corrupt or perhaps someone removed the file while the database was running. In any case, you need to take some proactive action before the problem has a more widespread impact.
In Oracle Database 11g, the new Data Recovery Advisor makes this operation much easier. The advisor comes in two flavors: command line mode and as a screen in Oracle Enterprise Manager Database Control. Each flavor has its advantages for a given specific situation. For instance, the former option comes in handy when you want to automate the identification of such files via shell scripting and schedule recovery through a utility such as cron or at. The latter route is helpful for novice DBAs who might want the assurance of a GUI that guides them through the process. I'll describe both here.
Command Line Option
The command line option is executed through RMAN. First, start the RMAN process and connect to the target.
$ rman target=/
Recovery Manager: Release 11.1.0.5.0 - Beta on Sun Jul 15 19:43:45 2007
Copyright (c) 1982, 2007, Oracle. All rights reserved.
connected to target database: PRODB3 (DBID=3132722606)
Assuming that some error has occurred, you want to find out what happened. The list failure command tells you that in a jiffy.
RMAN> list failure;
If there is no error, this command will come back with the message:
no failures found that match specification
If there is an error, a more explanatory message will follow:
using target database control file instead of recovery catalog
List of Database Failures
=========================
Failure ID Priority Status Time Detected Summary
---------- -------- --------- ------------- -------
142 HIGH OPEN 15-JUL-07 One or more non-system datafiles are missing
This message shows that some datafiles are missing. As the datafiles belong to a tablespace other than SYSTEM, the database stays up with that tablespace being offline. This error is fairly critical, so the priority is set to HIGH. Each failure gets a Failure ID, which makes it easier to identify and address individual failures. For instance you can issue the following command to get the details of Failure 142.
RMAN> list failure 142 detail;
This command will show you the exact cause of the error.
Now comes the fun part: How do you rectify the error? Seasoned DBAs will probably ace this without further help but novice DBAs (and even experienced but tired ones) will welcome some guidance here. They can turn to Data Recovery Advisor for assistance:
RMAN> advise failure;
It responds with a detailed explanation of the error and how to correct it:
List of Database Failures
=========================
Failure ID Priority Status Time Detected Summary
---------- -------- --------- ------------- -------
142 HIGH OPEN 15-JUL-07 One or more non-system datafiles are missing
analyzing automatic repair options; this may take some time
using channel ORA_DISK_1
analyzing automatic repair options complete
Mandatory Manual Actions
========================
no manual actions available
Optional Manual Actions
=======================
1. If file /home/oracle/oradata/PRODB3/users01.dbf was unintentionally renamed or moved, restore it
Automated Repair Options
========================
Option Repair Description
------ ------------------
1 Restore and recover datafile 4
Strategy: The repair includes complete media recovery with no data loss
Repair script: /home/oracle/app/diag/rdbms/prodb3/PRODB3/hm/reco_3162589478.hm
This output has several important parts. First, the advisor analyzes the error. In this case, it's pretty obvious: the datafile is missing. Next, it suggests a strategy. In this case, this is fairly simple as well: restore and recover the file. (Please note that I have deliberately chosen a simple example to focus the attention on the usage of the tool, not to discuss the many cases where the database could fail and how they can be recovered. The dynamic performance view V$IR_MANUAL_CHECKLIST also shows this information.)
However, the most useful task Data Recovery Advisor does is shown in the very last line: it generates a script that can be used to repair the datafile or resolve the issue. The script does all the work; you don't have to write a single line of code.
Sometimes the advisor doesn't have all the information it needs. For instance, in this case, it does not know if someone moved the file to a different location or renamed it. In that case, it advises to move the file back to the original location and name (under Optional Manual Actions).
OK, so the script is prepared for you. Are you ready to execute it? I don't know about you, but I would verify what the script actually does first. So, I issue the following command to "preview" the actions the repair task will execute:
RMAN> repair failure preview;
Strategy: The repair includes complete media recovery with no data loss
Repair script: /home/oracle/app/diag/rdbms/prodb3/PRODB3/hm/reco_741461097.hm
contents of repair script:
# restore and recover datafile
sql 'alter database datafile 4 offline';
restore datafile 4;
recover datafile 4;
sql 'alter database datafile 4 online';
This is good; the repair seems to be doing the same thing I would have done myself using RMAN. Now I can execute the actual repair by issuing:
RMAN> repair failure;
Strategy: The repair includes complete media recovery with no data loss
Repair script: /home/oracle/app/diag/rdbms/prodb3/PRODB3/hm/reco_3162589478.hm
contents of repair script:
# restore and recover datafile
sql 'alter database datafile 4 offline';
restore datafile 4;
recover datafile 4;
sql 'alter database datafile 4 online';
Do you really want to execute the above repair (enter YES or NO)?
Assuming I'm OK, I answer YES and the action goes on:
executing repair script
sql statement: alter database datafile 4 offline
Starting restore at 15-JUL-07
using channel ORA_DISK_1
channel ORA_DISK_1: restoring datafile 00004
input datafile copy RECID=5 STAMP=628025835 file name=/home/oracle/flasharea
/PRODB3/datafile/o1_mf_users_39ocxbv3_.dbf
destination for restore of datafile 00004: /home/oracle/oradata/PRODB3/users01.dbf
channel ORA_DISK_1: copied datafile copy of datafile 00004
output file name=/home/oracle/oradata/PRODB3/users01.dbf RECID=0 STAMP=0
Finished restore at 15-JUL-07
Starting recover at 15-JUL-07
using channel ORA_DISK_1
starting media recovery
archived log for thread 1 with sequence 51 is already on disk as file /home/oracle/
flasharea/PRODB3/archivelog/2007_07_15/o1_mf_1_51_39ocxxdw_.arc
... and so on ...
name=/home/oracle/flasharea/PRODB3/archivelog/2007_07_15/o1_mf_1_55_39ocy9ox_.arc thread=1 sequence=55
media recovery complete, elapsed time: 00:00:01
Finished recover at 15-JUL-07
sql statement: alter database datafile 4 online
repair failure complete
RMAN>
Note how RMAN prompts you before attempting to repair. In a scripting case, you may not want to do that; rather, you would want to just go ahead and repair it without an additional prompt. In such a case, just use repair failure noprompt at the RMAN prompt.
read more: "Oracle Database 11g: Top Features for DBAs and Developers" RMAN
Today’s trick is pretty simple, and it allows you to copy user accounts from one instance to another with the same password, grants, roles, etc, without using the exp/imp tools.
Everyone knows that you can use “create user username identified by password” to create a new user. What most people don’t know is that you can actually copy the password of a user from one database to another as well.
You wont be able to see the password (sorry hackers), but you can copy it in its encoded form.
Instead of using:
create user test identified by password;
You will use:
create user test identified by values 'encoded password';
The encoded password will actually be the encrypted password stored in the database that is visible to the DBA eye. This is a 16 character password you will find in the DBA_USERS view in the PASSWORD column.
You can also use:
alter user test identified by values 'encoded password';
If you have already created the user and need to change the password to what it might have been on another system.
This is extremely useful for DBAs that are copying their production database to development, or migrating a database from one instance to another. Too often, DBAs are forced to remember the details they have, copy them from the DBA_USERS view, and try to create the new users as close as possible to the original.
But we’re more sophisticated! Instead, we will use the DBMS_METADATA package to pull the user information.
set head off
set pages 0
set long 9999999
select dbms_metadata.get_ddl('USER', username) || '/' usercreate
from dba_users;
USERCREATE
--------------------------------------------------------------
CREATE USER "SYS" IDENTIFIED BY VALUES 'F894844C34402B67'
DEFAULT TABLESPACE "SYSTEM" TEMPORARY TABLESPACE "TEMP"
/
...
Do you want to get all their roles and grants as well? Nothing easier! Look at the following:
SELECT DBMS_METADATA.GET_GRANTED_DDL('ROLE_GRANT','SYS') FROM DUAL;
SELECT DBMS_METADATA.GET_GRANTED_DDL('SYSTEM_GRANT','SYS') FROM DUAL;
SELECT DBMS_METADATA.GET_GRANTED_DDL('OBJECT_GRANT','SYS') FROM DUAL; From this, we can form our Unified User Copy-o-matic with the following query:
set head off
set pages 0
set long 9999999
spool user_script.sql
SELECT DBMS_METADATA.GET_DDL('USER', USERNAME) || '/' DDL
FROM DBA_USERS
UNION ALL
SELECT DBMS_METADATA.GET_GRANTED_DDL('ROLE_GRANT', USERNAME) || '/' DDL
FROM DBA_USERS
UNION ALL
SELECT DBMS_METADATA.GET_GRANTED_DDL('SYSTEM_GRANT', USERNAME) || '/' DDL
FROM DBA_USERS
UNION ALL
SELECT DBMS_METADATA.GET_GRANTED_DDL('OBJECT_GRANT', USERNAME) || '/' DDL
FROM DBA_USERS;
spool off;
And voila! All of our users and grants all in one simple script.
If you would like simple alter commands instead, we can always skip using DBMS_METADATA. Instead, use this query:
select 'alter user ' || username ||
' identified by values ''' || password || ''';'
from dba_users;
Note that in the case above, there are three single quotes to the left and right of password. Don’t use double quotes.
That’s it for today; a rather easy trick that you can use many times during your DBA career. If you already knew this trick, don’t worry! There’s more to come, the rest a bit more advanced and a bit more obscure. Join me tomorrow and we’ll talk about how to transform any query into any other on the back-end, sometimes with very amusing results!
Ref : http://www.oraclealchemist.com/news/trick-1-copying-users-the-right-way/
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