There are lots of differences. For example there is no VARCHAR data type in Oracle, you’ll have to use VARCHAR2 instead. Using user defined functions is basically the same.
The big difference is that SQL Server using T/SQL and Oracle uses PL/SQL as the programming language. All the code within the procedure will need to be changed from T/SQL to PL/SQL. Kevin Kline has a good out which shows a lot of the differences between the two.
use the Oracle Golden Gate
First you need a copy of Oracle GoldenGate v11 for SQL Server. You can download it from http://edelivery.oracle.com (Oracle Fusion Middleware → Microsoft Windows x32 → Oracle GoldenGate for Non Oracle Database v11). The serial number of the media pack that you need is V22241-01.
you can consult
just follow the instructions, and you will have all your database and functions translated to Oracle.