Updating a table using cursor is taking long time in oracle

Question

Hi,
I am working on the oracle database 11gR2. I am trying update a table column which is newly added through cursor. below is the cursor.
BEGIN
     FOR lcur_tab IN (select l.LOGIN_ID as login_id, lt.ERROR_CODE as error_code from LOGIN l INNER JOIN LOGIN_TASK lt ON (l.LAST_LOGIN_TASK_ID = lt.LOGIN_TASK_ID) )
     LOOP
               UPDATE ACCOUNT SET LOGIN_ERROR_CODE = lcur_tab.error_code where ACCOUNT_ID IN (SELECT ACCOUNT_ID FROM LOGIN_ACCOUNT where LOGIN_ID = lcur_tab.login_id ) ;
     end LOOP;
     commit;
END;
In the cursor we are trying to copy the Login table error_code value to LOGIN_ERROR_CODE of ACCOUNT Table, for the accounts associated with that Login. Here newly added column is LOGIN_ERROR_CODE in account table. this account table have 11million rows in it. when i used the above cursor it took 3hours and still running. So we stopped after that. Is there any way i can change this cursor syntax to update those column values. How can we do this type of updates?
Also i am planning to run thus update in the background . I don't have much knowledge on the PL/SQL stuff. So please help on this.
Thanks in advance.
Edited by: Hari on Mar 21, 2012 10:06 PM

Answer 1

Is there a reason that you don't want to do this with a single `UPDATE` statement? That should be quite a bit more efficient.
Something like
UPDATE account a
   SET login_error_code = (
      select lt.error_code
        from login_task lt
             join login l on (l.last_login_task_id = lt.login_task_id)
             join login_account la on (la.login_id = l.login_id)
       where la.account_id = a.account_id )
WHERE EXISTS (
      select 1
        from login_task lt
             join login l on (l.last_login_task_id = lt.login_task_id)
             join login_account la on (la.login_id = l.login_id)
       where la.account_id = a.account_id );Justin