Today I planned to test “Recover the datafile without prior backup”

Currently there is no failure in database. I shutdown the database & removed the below datafile in OS level “D:\ORACLE\APP\ORADATA\CHE\TEST.DBF”.

Note:

1.Database must be in archive log mode.
2.We need all the archive log files from lost datafile created.

1.Login into che database

C:\>set oracle_sid=CHE

SQL*Plus: Release 11.1.0.7.0 - Production on Wed May 19 14:21:03 2010

Copyright (c) 1982, 2008, Oracle.

Oracle Data Recovery Advisor 11g new feature

Data recovery advisor is one of the oracle 11g new features.

The Data Recovery Advisor tool can assist with diagnosing media failures, making recommendations and providing the RMAN commands to resolve the problem.

Data Recovery advisor we have used three commands.

1.List failure
2.Advice failure
3.Repair failure

How it works?

1.List failure:

The Data Recovery Advisor stores its information outside the database in the Automatic Diagnostic Repository (ADR - V$diag_info)

If you find any problem in database and Data recovery a

Security is gaining importance. As per the reports in the year 2008, loss of confidential information has increased to 63%. This loss of confidential information is a breach of Service Level Agreement (SLA). Organizations will have to compensate these loses in the form of financial penalties.
A recent information protection law from a state in U.S.A claims that information of residents of this state stored in databases across the globe will have to be encrypted. Upon failure, the database owners will have to pay $5000 penalty.

Oracle installation: Oracle Binary Cloning

Clone the oracle software between two server.

Please check the OS compatibility are same between source & destination server.

Source Server:
****************

steps 1:

ORACLE_HOME: /apps/oracle/product/10.2.0.1

Tar the oracle home 10.2.0.1

$cd /apps/oracle/product

$tar -cvf 10.2.0.1.tar 10.2.0.1

Destination server:
******************

Steps 2:

Copy the oracle binary tar file from source server to Destination server.

$mkdir -p /apps/oracle/product

$cd /apps/oracle/product
$sftp oracle@source

DBA’s faced data fragmentation issues frequently. Data fragmentation affects the database performance.
In production database, we need to follow any one of the below method to solve the fragmentation issue.
Methods:

1. Alter table move tablespace ;
--- Also we need to rebuild the indexes associate with tables.
2. Export the table / truncate the table / import the table
3. Create table as select (CTAS)
4. Online Data Redefinition
Table is not accessible for during the reorganization of table using Method 1, 2 & 3.

RAC Background Processes:

1. Lock Monitor Processes ( LMON)
2. Lock Monitor Services (LMS)
3. Lock Monitor Daemon Process ( LMD)
4. LCKn ( Lock Process)
5. DIAG (Diagnostic Daemon)

1.

I recently came across a document where the requirement was to convert from triple/double byte characters to single byte characters to send it for export complaince check as the export compliance system can accept only single byte characters.
Basically the useful thing about this was they were using IBM ICU project(an open source project) for this process,so in a way making it more open to developers.
These were the pros and cons for IBM identified by them.
Pros
- No interface needed (written in Java, integrable in Oracle)
- High level of portability, flexibility and scalability
- No int

Error:Heartbeat failed to connect to standby Error 12541
By using rdist command, one can copy Oracle's password file from primary site to physical standby site.

Last week I migrated some schemas from 11g database (11.1.0.6) to 9i database (9.2.0.8).

I used to export the 11g schemas using oracle 9i binary & exported successfully.
While importing 11g schema’s into 9i database I faced below issues.

Error: import done in US7ASCII character set and AL16UTF16 NCHAR character setSegmentation Fault (coredump)

Operating system: Sun Solaris 10 / 64 bit processor

Note:

I exported the 11g schema’s using 10g binary and imported into 10g database
successfully.

Last week, I worked on schema refresh in 11g database from one box to another box using data pump.

Schema size: around 90 GB.
Version: 11.1.0.7

Method 1:

Normally we follow below steps: (I have sufficient space in file system, so I am using below steps)
1.Export the schema using expdp/exp utility.
2.Compress the dump file.
3.Transfer the data through ftp to another box.
4.Just import it.

Step 2, depend upon dump size.

Note:
I have sufficient space in file system, so I am using method 1.

Method 2:

1.Export the schema using expdp/exp utility (during export they used