Hi,
I have two oracle databases db1 & db2 residing on the same server
i need to write a query joining one table from db1 and other from db2
how can i do this?

Create a database link.

You have the two databases: "Database1" and "Database2".
In "Database1", create a link to "Database2"

like so: (logged in as user with create link privilege)
create public database link "Database2"

connect to "Database2user" identified by "Database2userpassword" using "Database2";
Then in Database1, you should be able to write a select statement along these lines:

SELECT tab1.col1, tab2.col2 FROM table1 tab1 --table in "Database1",table2@"Database2" tab2 --table in "Database2"

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Om Prakash Pant

thanks .. is there any other way other than creating dblink..

You have to create dblink to connect two different databases.

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Regards
Debasis