SQL Update take long time with First_Value function

Question

I have two table KYCCUST and FINACLE_TEMP_in_kyc1. They are in different databases then I want to do some update.

UPDATE  KYCFBHK.KYCFBHK.KYCCUST
SET KYC_SP_08=
(SELECT DISTINCT FIRST_VALUE(KYC_SP_08) over (partition by CUSTNO order by DATE desc) FROM AMLETL.dbo.FINACLE_TEMP_in_kyc1 t1 

WHERE CUSTNO collate Latin1_General_BIN2 = KUNDNR AND HISTBIS ='9999')

WHERE HISTBIS = '9999'

The sub query "Select First_value" return result in 10 secs but when I do the update. It took 1hours and still not yet finish. Can we reduce time run? Our DBMS is MSSQL Server 2016. And in these tables, we also have index.

Answer 1

It worked with query below:

update T1
SET T1.KYC_SP_08=T2.Kyc_sp_08 
from KYCFBHK.KYCFBHK.KYCCUST T1 
Inner join AMLETL.dbo.FINACLE_TEMP_in_kyc1 T2
ON T2.CUSTNO  COLLATE Latin1_General_BIN2 = T1.KUNDNR
And T1.HISTBIS=9999
And T2.Date in (select max(date) from AMLETL.dbo.FINACLE_TEMP_in_kyc1)