The skill of searching

The skill of searching is one of the most important skills you need these days to survive.
The communication on the net is another one.

Ignorance is the opposite.

Just to kick-start your skilling:
when searching:
clearly state the question/request:
in your case: "I need a sql to delete duplicate rows in oracle table"
cut the overhead out:
delete duplicate rows

Go through some of the items on top, and if you didn't find the answer - then your keywords are wrong.

When all other fails - ther eare many other search engines.
My personal preference is Google, but feel free to use any other. When searching on the generic search engine, you should include the keyword "Oracle".
Let's see if this is good for you:
http://www.google.com/search?q=oracle+delete+duplicate+rows

If you didn't find the answer in the first five references - your list of keywords is wrong!

If you want to learn moer about the searching from master Fravia:
http://www.searchlores.org/


Also - it pays to educate in the general communication skills on the net.
Seatch on netiquette on google:
http://www.google.com/search?hl=en&lr=&q=netiquette
then read a bit.
When ready - come back with some real questions.
Good luck