ALTER SYSTEM is not executing in jruby - oracle

Question

I am trying to execute plsql block in which I have ALTER USER and then ALTER SYSTEM statements one after other. ALTER USER is executing but ALTER SYSTEM is not.
My code does the following:
1. Connects to the database using jdbc driver.
2. Changes the login user of a particular user (here I am using ALTER USER statement).
3. Kills the session of that particular user before dropping it (here I use ALTER SYSTEM statement which is not running).
Below is the code fragment which is not running for me.
users = ['ABC', 'XYZ']
$users.each do|x|
if( is_usr?("#{x}") )
puts "Working on #{x}"
stmt = <<-EOF
DECLARE
id NUMber(10);
s_num NUMBER(10);
CURSOR cur IS
SELECT sid, serial#
FROM v$session WHERE username like ('#{x}');
BEGIN
OPEN cur;
LOOP
FETCH cur INTO id, s_num;
dbms_output.put_line(id||' '||s_num);
EXECUTE IMMEDIATE 'ALTER USER #{x} IDENTIFIED BY dummypass';
EXECUTE IMMEDIATE 'ALTER SYSTEM KILL SESSION ''' ||id|| ',' ||s_num||'''';
EXIT when sess_cur%notfound;
END LOOP;
CLOSE cur;
END;
EOF
puts "#{stmt}"
plsql = #conn.create_statement
plsql.execute_update(stmt)
else
puts "#{x} does not exist"
end
end
Output looks like this:
Working on ABC
DECLARE
id NUMber(10);
s_num NUMBER(10);
CURSOR cur IS
SELECT sid, serial#
FROM v$session WHERE username like ('ABC');
BEGIN
OPEN cur;
LOOP
FETCH cur INTO id, s_num;
dbms_output.put_line(id||' '||s_num);
EXECUTE IMMEDIATE 'ALTER USER ABC IDENTIFIED BY dummypass';
EXECUTE IMMEDIATE 'ALTER SYSTEM KILL SESSION ''' ||id|| ',' ||s_num||'''';
EXIT when sess_cur%notfound;
END LOOP;
CLOSE cur;
END;
Working on XYZ
DECLARE
id NUMber(10);
s_num NUMBER(10);
CURSOR cur IS
SELECT sid, serial#
FROM v$session WHERE username like ('XYZ');
BEGIN
OPEN cur;
LOOP
FETCH cur INTO id, s_num;
dbms_output.put_line(id||' '||s_num);
EXECUTE IMMEDIATE 'ALTER USER XYZ IDENTIFIED BY dummypass';
EXECUTE IMMEDIATE 'ALTER SYSTEM KILL SESSION ''' ||id|| ',' ||s_num||'''';
EXIT when sess_cur%notfound;
END LOOP;
CLOSE cur;
END;
Observation after running this script:
1. I am able to login to db as ABC and XYZ with 'dummypass' as password. Hence I know that ALTER USER statement has been run successfully.
2. I still see all the same session ids and serial#s for 'ABC' and 'XYZ'. Hence I know that ALTER SYSTEM statement did not run.
I am struggling in fixing this one since past 3-days. Please help me in fixing this. Thanks in advance.

Answer 1

ALTER SYSTEM KILL SESSION does not instantly get rid of the session. It only marks it for being killed. Normally a background process will get rid of it in a minute. If there are many uncommitted changes it can take a very long time to rollback everything.
There is no way to speed up the process. The best you can do it ignore those sessions with a predicate like where v$session.status <> 'KILLED'.