I found useful blog post on how yo become a Data Scientist,here. There’re so much cool stuffs to learn about Big Data and hadoop.One of my favourite is datasciencecentral .
Oracle 12c June 26, 2013
Oracle 12c Database (12.1.0.1.0) is available for download under http://edelivery.oracle.com/
How to block developing tools on Database March 23, 2012
CONNECT / AS SYSDBA;
CREATE OR REPLACE TRIGGER block_tools_from_prod
AFTER LOGON ON DATABASE
DECLARE
v_prog sys.v_$session.program%TYPE;
BEGIN
SELECT program INTO v_prog
FROM sys.v_$session
WHERE audsid = USERENV(‘SESSIONID’)
AND audsid != 0 — Don’t Check SYS Connections
AND ROWNUM = 1; — Parallel processes will have the same AUDSID’s
IF UPPER(v_prog) LIKE ‘%TOAD%’ OR UPPER(v_prog) LIKE ‘%T.O.A.D%’ OR — Toad
UPPER(v_prog) LIKE ‘%SQLNAV%’ OR — SQL Navigator
UPPER(v_prog) LIKE ‘%PLSQLDEV%’ OR — PLSQL Developer
UPPER(v_prog) LIKE ‘%BUSOBJ%’ OR — Business Objects
UPPER(v_prog) LIKE ‘%EXCEL%’ — MS-Excel plug-in
THEN
RAISE_APPLICATION_ERROR(-20000, ‘Development tools are not allowed here.’);
END IF;
END;
/
SHOW ERRORS
Security in the Database Oracle 11g March 19, 2012
We have seen the most awful of technology either stolen or lost your data on Databases especially Oracle has improved security through the newer version of Oracle 11g
Oracle 11g provides transparent data encryption at a tablespace level, and this video presents practical ways to look at security and implementing standards and procedures around the database environment to account for the security outside of the users, including secured environments for regulations and compliance.
Deadlock ORA-00060 error August 22, 2011
What is deadlock?
Deadlock is a situation in which two or more users are waiting for data locked by each other. deadlocks prevent some transactions from continuing to work.
How to resolve deadlock?
We have to do nothing to resolve deadlock error (ORA-00060), oracle automatically detects and resolve the deadlock by rolling back one statement involve in the statement. releasing one set of conflicting row locks.
Why deadlock error occurs?
deadlock is completely application bug. ask DEVELOPER to look into the coding on particular form (query) which raise DEADLOCK.
What is the reason for deadlock?
Deadlocks most often occur when transactions explicitly override the default locking of oracle database. because oracle database not escalate locks and does not use read locks for queries. but does use row-level locking, deadlocks occurs infrequently.
Video Tutorial – Installing Oracle 10gR2 Grid Control and deploying agent on Linux and Windows OS June 27, 2011
Oracle Grid Control managing lots of databases and application servers It can manage multiple instances of Oracle deployment platform.Click here for the video tutorial of how to install Oracle 10gR2 Grid Control.
SYSDBA v/s SYSOPER July 20, 2010
SYSDBA and SYSOPER are administrative privileges required to perform high-level administrative operations such as creating, starting up, shutting down, backing up, or recovering the database. The SYSDBA system privilege is for fully empowered database administrators the highest system privilege in oracle But SYSOPER system privilege is limited than SYSDBA. SYSOPER system privilege allows a user to perform basic operational tasks, but without the ability to look at user data.
In the following section, the following listed the operation that a user can perform who is authenticated as SYSDBA and SYSOPER system privilege.
SYSDBA:
• Perform STARTUP and SHUTDOWN operations
• ALTER DATABASE: open, mount, back up, or change character set
• CREATE DATABASE
• DROP DATABASE
• CREATE SPFILE
• ALTER DATABASE ARCHIVELOG
• ALTER DATABASE RECOVER
• Includes the RESTRICTED SESSION privilege
• Allows a user to connect as user SYS.
SYSOPER
• Perform STARTUP and SHUTDOWN operations
• CREATE SPFILE
• ALTER DATABASE OPEN/MOUNT/BACKUP
• ALTER DATABASE ARCHIVELOG
• ALTER DATABASE RECOVER (Complete recovery only. Any form of incomplete recovery, such as UNTIL TIME|CHANGE|CANCEL|CONTROLFILE requires connecting as SYSDBA.)
• Includes the RESTRICTED SESSION privilege
• Allows a user to perform basic operational tasks, but without the ability to look at user data
How to become an Oracle DBA July 19, 2010
I came across a very useful article by Burleson Consulting how to become an Oracle DBA.
Every year, young computer professionals leave the hallowed halls and ivory towers of college and survey the landscape for computer jobs. They look at the salary surveys and drool at the average Oracle DBA salary of $100,000 and the prospect of earning up to $250,000 per year as a production DBA. Many of them don’t know what a DBA does, but they sure like the money.
U.S. government sues Oracle for tens of millions of dollars June 18, 2010
The U.S. government is suing Oracle Corp. for denying it significant discounts on software purchases the vendor routinely gave to its commercial customers. The government is claiming damages as high as $169 million in the Oracle lawsuit.Go and read it
Oracle DBA 