Hi,
below is a brief overview on the environment that we have:
SQL 2005 server is been used.
SQL 2005 SP2 is installed.
Database size: 1.2 TB
Temp_Table size: av. 2.7 GB, av. No of records: 3500000
Destination_Table size: 400079 MB Row Count: 535851739, partitioned and there is no PK constraints.

we have a .dtsx package that do some tasks and at the end there is a "Data Flow" task that do nothing else then moving the data from the Temp_Table to the Destination_Table this task is taking around 3 days to be completed !!
can you please advise what could be going wrong?

Have you tried executing the INSERT statement in SQL?

No We didnt try the insert since it is a production environment, do you think the insert will be faster?

Don't you have a test environment? I don't know if it will be faster.