Re: Speedup the dml ??

feib wrote:
>
> Hello, there
> I have two tables a,b ( a with 600000 records, b 60000 records)
> Both a and b have the same columns c1 c2 c3 c4 c5.
> I want to update a's c5 by b's c5 for the same key value c1-c4.
> So,I create two unique indexies on a(c1,c2,c3,c4) and b(c1,c2,c3,c4).
>
> update a
> set c5 = ( select c5
> from b
> where a.c1=b.c1
> and a.c2=b.c2
> and a.c3=b.c3
> and a.c4=b.c4 );
>
> Are there any better statement ( like EXISTS,or any hint to speedup) ??
> Any ideas ??
>
> Rgds,
> Agi Chen
>
>
>

Try updating the join directly (this will work if you have the appropriate primary keys)

HTH

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk

We are born naked, wet and hungry...then things get worse