Preformance issue with Dense_Rank

Question

well....

I have a table containing 400,000 records.

I'm trying to combine the records and i am using Dense_Rank

Only problem ? after 10 hours of running i still got nothing.

DENSE_RANK()OVER(PARTITION BY FirstName, LastName,HouseNumber,Address,City,State,Zip ORDER BY ISNULL(email,'')DESC) AS RNum_Email
          ,DENSE_RANK()OVER(PARTITION BY FirstName, LastName,HouseNumber,Address,City,State,Zip ORDER BY ISNULL(PhoneNumber,'')DESC) AS RNum_PhoneNumber

Any alternatives ?

Hardware a dell server with 2 E5-2620 V3 and 40 GB Ram.

Answer 1

drop table if exists #tempResults;

;with cte as (...) -- cte here

select * into #tempResults from cte

update myRealTable set ...
from myRealTable inner join #tempResults t on ....