update several rows from a select???

update tbl r set
(c1, c2, c3,c4,

            c5, c6, c7)=
 ( SELECT distinct c1, c2, c3,c4,

            c5, c6, c7
		  from tbl i
		  where i.c8= r.c8
		  and i.c7> r.c7
		  )

i am trying to update several rows from a select this rows can be up to 500k.
this is a huge time consuming for this.

Is it a better way of doing it???

Thanks in advance

A Received on Mon May 07 2007 - 10:53:11 CDT