Writing a BULK Update for a Update statement

Question

I want write(convert) this Query in PL/sql code using Bulk Collect and Update since this query is taking more time to execute. How I can achive this ?
Please Help me.
UPDATE my_master aa
SET (pay_date, last_mod_by, last_mod_date, verified_status) =
(SELECT TO_DATE ('03/09/2007', 'dd/mm/yyyy'), 'S1',
TO_DATE ('22/02/2008', 'dd/mm/yyyy'), 'Y'
FROM dtl_1 a, dtl_2 b
WHERE a.br_id = b.nr_id
AND aa.acct_num = a.acct_num
AND TO_DATE (TO_CHAR (aa.dat1, 'mm/yyyy'),
'mm/yyyy'
) <
TO_DATE (TO_CHAR (a.dat1, 'mm/yyyy'),
'mm/yyyy'
WHERE (acct_num) =
(SELECT a.acct_num
          FROM dtl_1 a, dtl_2 b
WHERE a.br_id = b.nr_id
aa.acct_num = a.acct_num
AND TO_DATE (TO_CHAR (aa.dat1, 'mm/yyyy'),
'mm/yyyy'
) <
TO_DATE (TO_CHAR (a.dat1, 'mm/yyyy'),
'mm/yyyy'
AND dat1 <
(SELECT a.dat1
FROM dtl_1 a, dtl_2 b
WHERE a.br_id = b.nr_id
aa.acct_num = a.acct_num
AND TO_DATE (TO_CHAR (aa.dat1, 'mm/yyyy'),
'mm/yyyy'
) <
TO_DATE (TO_CHAR (a.dat1, 'mm/yyyy'),
'mm/yyyy'
))

Answer 1

"More" is a relative term. More than what? Perhaps you just mean it is taking a long time and you think it should be possible to make it faster.
First, if I tidy up the query and simplify the date expressions so it's easier to read, I get this, which should give the same results (but not be any faster):
UPDATE my_master aa
SET    ( pay_date, last_mod_by, last_mod_date, verified_status ) =
       ( SELECT DATE '2007-09-03', 'S1', DATE '2008-02-22', 'Y'
         FROM   dtl_1 a
              , dtl_2 b
         WHERE  a.acct_num = aa.acct_num
         AND    TRUNC(aa.dat1,'mm') < TRUNC(a.dat1,'mm')
         AND    b.nr_id = a.br_id )
WHERE  acct_num =
       ( SELECT a.acct_num
         FROM   dtl_1 a
              , dtl_2 b
         WHERE  a.acct_num = aa.acct_num
         AND    TRUNC(a.dat1,'mm') > TRUNC(aa.dat1,'mm')
         AND    b.nr_id = a.br_id )
AND    dat1 <
       ( SELECT a.dat1
         FROM   dtl_1 a
              , dtl_2 b
         WHERE  a.acct_num = aa.acct_num
         AND    TRUNC(a.dat1,'mm') > TRUNC(aa.dat1,'mm')
         AND    b.nr_id = a.br_id );If so, I'm a bit confused by the second subquery. Don't you already compare dat1 in the first subquery? I can't test this but isn't it the same as:
UPDATE my_master aa
SET    ( pay_date, last_mod_by, last_mod_date, verified_status ) =
       ( SELECT DATE '2007-09-03', 'S1', DATE '2008-02-22', 'Y'
         FROM   dtl_1 a
              , dtl_2 b
         WHERE  a.acct_num = aa.acct_num
         AND    TRUNC(aa.dat1,'mm') < TRUNC(a.dat1,'mm')
         AND    b.nr_id = a.br_id )
WHERE  EXISTS
       ( SELECT NULL
         FROM   dtl_1 a
              , dtl_2 b
         WHERE  a.acct_num = aa.acct_num
         AND    TRUNC(a.dat1,'mm') > TRUNC(aa.dat1,'mm')
         AND a.dat1 > aa.dat1
         AND    b.nr_id = a.br_id );Although if a.dat1 is in a later month than aa.dat1 then the second check is redundant anyway.
Message was edited by:
William Robertson