database_link

can u help me??

yes, using Oracle Transparent Gateways:
http://www.oracle.com/technology/documentation/gateways.html

never did it yet myself, however

it is more confusing and could u help me with something else...

>right and is it possible to access from non-oracle database?
yes, using transparent gateways. however, not all non-oracle databases can be accessed like that, and for each product you will need to install and configure it's own transparent gateway.
hence, the lot of documentation that you found in the link above.

>an u give me an example to create database link in between oracle and between oracle and non-oracle database?
as I never did it myself, and especially as you did not specify which other database, it will not be possible for me.

can u provide me some syntaxes??

If you don't read what I (or someone else) write, it will be difficult to learn!
let me repeat:
::as I never did it myself, and especially as you did not specify which other database, it will not be possible for me.

thanks