thank you for responding me.i want to copy tables from sql databse to oracle database and tables are not in flat file format.i know we can do it using sql loader but it is time consuming bcoz i have to copy 50 tables.is there any other alternative other than sql loader ?.
You haven't said if this is a one-off copy of the data or if it is comething you want to do on a regular basis.
If it is a one-off move of the data then you could use the SQL*Developer migration workbench, see here for more details -
SQL*Developer main page -
If it is something you want to do on a regular basis then you could use a gateway to make a connection between SQL*Server and Oracle and then copy or select from the remote tables.
The following page has more detail -