SQL Server large data volume insertion and index relationships

If the table contains clustered indexes and the data to be inserted is sorted to match the clustered index key, the data will be copied to a table with a clustered index andOrder
Prompt.
This is faster than copying data to a table before creating a clustered index.

If there are non-clustered indexes in the table, delete these indexes and then copy the data to the table.
If you copy a large volume of data to a table without a clustered index and re-create a non-clustered index, it is generally faster than copying a large volume of data to a table with a non-clustered index.