You can truncate the EIM table to delete the existing rows from the EIM table. If you run the same EIM task on an EIM table multiple times, you must truncate the EIM table before you process the same batch number again.
You can also truncate the existing rows from the EIM tables to enhance the performance of the EIM task. The PowerCenter Integration Service takes a longer time to perform actions on an EIM table that contains many rows. When possible, truncate the table to reduce the size of the table.