autocommit and stored procedures

Hi,

Which command granularity does the JDBC driver's autocommit have?
Does it commit after each client-side JDBC statement, or does it commit
each individual SQL statement on the server-side?
In particular, does an JDBC autocommit around the call to a stored
procedure
commit each statement within that stored procedure, or does it commit
the
procedure as a whole?

Example:

Stored Procedure
----------------
CREATE PROCEDURE Test (n varying character,val REAL)
DECLARE
cid INTEGER;
BEGIN
SELECT custid INTO cid
FROM account
WHERE name=n;

UPDATE checking
SET balance=balance-val
WHERE custid=cid;
END;

JDBC Code
---------
Connection conn;
CallableStatement cstmt;
conn.setAutoCommit(true);
cstmt = conn.prepareCall("{call Test(?,?)}");
cstmt.setString(1, name);
cstmt.setString(2, value);
cstmt.execute();

Does PostgreSQL execute one commit after the execution of Test(),
i.e. do select and update run in one transaction?
Or will PostgreSQL commit after the select and then again after the
update
inside the Test() procedure?

Does anyone know what the specified behaviour is for JDBC AutoCommit?

Many thanks

Uwe