Re: Two records a year apart

Hi Philip

Try this

UPDATE mcd.sumps a

   SET a.comp = 1
 WHERE EXISTS ( SELECT b.mstore

                  FROM mcd.sumps b
                 WHERE a.mstore = b.mstore
                   AND   a.mperiod
                       - b.mperiod > 365)

sometimes, EXISTS clause is more efficient then the IN clause

hth
Chris

"Philip Morrow" <cracker_at_mymorrow.com> wrote in message news:<_ZY08.319763$oj3.65754398_at_typhoon.tampabay.rr.com>...
> I've got a table similar to this
>
> mperiod date
> mstore number
> tc number
> tq number
> tp number
> comp number
>
> I'm using this SQL to determine if, for any one record of say store 154 if
> there is a corisponding record for that store one year prior. It seems to
> be taking a long time... any suggestions on a different way to do this would
> help, or suggestions on a better way to write this SQL would help too.
>
> The explain plan lists two full table accesses.
>
> update mcd.sumps a set a.comp = 1 where a.mstore in (
> select b.mstore from mcd.sumps b where (to_date(a.mperiod) -
> to_date(b.mperiod)) = 365);
Received on Tue Jan 15 2002 - 18:01:52 CST