Rollback in procedure called over dblink - sql

Question

I have strange situation
It's bit hard to explain but I'll do my best
There are 3 different database included
From DB1 I call function on DB2 (over dblink)
That procedure calls another procedure that inserts data into table on DB3
Function on DB2 has EXCEPTION handle that should rollback everything that it did in case of exception
I did example run, and everything went well (there was no error) but insert from procedure 3 was not rollbacked and I have to rollback from DB1 to truly rollback
If i commit from db1, row is inserted
Am I doing something wrong and is there a way to rollback directly from function on db2
Here is some example code:
--DB1
PROCEDURE 1
BEGIN
x := function2#dblink_to_db2();
END;
--DB2
FUNCTION 2
BEGIN
procedure3();
RAISE SOME EXCEPTION;
EXCEPTION
WHEN OTHERS THEN
ROLLBACK;
do_something_else();
RETURN 0;
END;
PROCEDURE 3
BEGIN
INSERT INTO tableA#dblink_to_db3 VALUES ... ;
END;
So no error is raised but insert into table on db3 is not rollbacked

Answer 1

You must be having a commit somewhere in your code either before the raise exception or in Procedure3. I just tested the below code and it rolledback everything before the exception. Please ignore the naming conventions, had to go due to time constraint.
Database 3
CREATE TABLE temp
(col1 NUMBER);
create or replace procedure testp(i number)
as
BEGIN
INSERT INTO temp VALUES (i);
END;
/
Database2
CREATE OR REPLACE FUNCTION DLR_TRANS.testf(i number)
return number
as
e exception;
BEGIN
testp#TO_DB3(i);
RAISE e;
EXCEPTION
WHEN OTHERS THEN
ROLLBACK;
RETURN 0;
END;
/
database1
declare
x number;
BEGIN
x := testf#TO_DB2(15);
DBMS_OUTPUT.PUT_LINE ( 'x = ' || x );
commit;
END;
x returns 0 due to exception in DB2's function.
And below is the data when I ran the below statement on DB3
select * from temp;
Hope this helps

Answer 2

The problem is that you have "handled" the exception in [function 2]. You should not put the exception block in [function 2] at all. And let the exception propagate up to [procedure 1]. Here you will implicitly or explicitly rollback.
If you must have an exception block in [function 2] then you should have a [raise] at the end. Handling the exception like this is saying [I have handled it and for all practical purposes the caller of this should not think anythibg bad has happened]