Could you show your update query?
Did you analyze plan?
Did you change any parameter of the database?
Did you change any kernel parameters of the OS ?
What is the size of update-able table?
How many indexes table have?
Did you have any after/before update trigger?
Share the explain plan for the same.
Can you share the SQL and explain plan ? Also did you check the statistics on the tables the query is accessing? Check the plan history and see if they is any change in plan since yesterdays run
And a couple of more questions:
Do you have much more data?
Is there something else running that normally wouldn't be running at that time? It can help to look at a statspack or AWR for the time in question.
Did you try turning it off and turning it back on again?
Daily update statement takes 20 mins. But today update takes more time.
What is the reason how to resolve ?
Thanks in advance ..
More time? How much more?