How to improve the updating a sql server table with another table in Oracle

Hi there.

I am trying to do the next updating in SSIS

UPDATE S
SET
S.COLUMN_A = OT.COLUMN_A,
S.COLUMN_B = OT.COLUMN_B
FROM 
SQLT1 S INNER JOIN ORACLET1  OT ON
S. COLUMN_C = OT.COLUMN_C

This is what I am doing:

I am taking the Oracle data with the ODBC Source like this.

Select column_A, column_B, column_C

from OracleT1

The thing is, the Oracle table has millions of registers and this updating is taking a lot. But I am not sure if it is maybe because of the design of the update query.

I wonder is if there is another way to design this query or improve the performance of this task.

Thanks a lot.