Question

update auditdata set TATCallType='12',TATCallUnit='1' from auditdata auditdata 
        inner join Auditdata_sms_12 a_sns
        on auditdata.ID = a_sns.id

when I above query it takes more than 10 minutes to execute.

what wrong in this

Auditdata.ID is primary key..

if i run Update command is that also update the indexes???
is this reason of update getting is slow

Answer 1

Looking at your comment, main table contains less rows than temp table.

Try using EXISTS clause (or in some sense, reduce the comparison to less number of rows (i.e. 1500000)

update auditdata set TATCallType='12',TATCallUnit='1' 
from auditdata auditdata 
WHERE EXISTS 
(SELECT id from Auditdata_sms_12 a_sns WHERE a_sns.id = auditdata.ID)

The idea is to limit the comparisons.

EDIT: AuditdataSMS12 should have the index on ID to be able to get the row quickly. That is the table you are actually looking up for a given ID.