ORA-15027: active use of diskgroup “DATA” precludes its dismount

As i wanted to test few thing related to asm diskgroup on my test box, had to drop the diskgroup. Before dropping the diskgroup had dropped the database using RMAN. A S M D I S K G R O U P S P A C E U S A G E R E P …

Optimizer Statistics Whitepaper

The CBO team has released two white papers on Optimizer.The first paper was released in Nov 2011, which was titled "Understanding Optimizer Statistics" and this month Apr 2012, they have released "Best Practices for Gathering Optimizer Statistics". I would say its a must read. https://blogs.oracle.com/optimizer/entry/lies_damned_lies_and_statistics https://blogs.oracle.com/optimizer/entry/lies_damned_lies_and_statistics1 Also Timur Akhmadeev has started Poll on the METHOD_OPT …

Enq: FB contention – No its not Facebook Contention

I am not a facebook fan neither an addict of it, but i still got to see "enq: FB contention"...thats bad :). Well this was for the first time i saw this wait event and it was on 11.2.0.2 version.Mostly, the enq: FB contention wait event was followed by log buffer space. Well, the enq: …

oracle-hot-backup-concept – Revisitied!!!

In 2010 i had posted the blog with the hot backup concept which was explained by Howard (aka,HJR on Forums) - https://aprakash.wordpress.com/2010/06/27/oracle-hot-backup-concept/ Recently i read another blog by "Jeremiah Wilton" who has explained it very well, so i thought of posting it for my future reference as well as for few others who might have …