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Home -> Community -> Usenet -> c.d.o.server -> Re: Two records a year apart
Try something like
update mcd.sumps a set a.comp = 1
where exists
( select * from mcd.sumps b
where a.mstore = b.mstore and b.mperiod = add_months( a.mperiod, -12 )
)
Assuming an index on mstore,mperiod, this should report 1 full table scan and 1 index search.
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 - 14:31:01 CST