0 - 1 of 1 tags for dynamic lookup

Hi all,
Was wondering if there is anything like dynamic lookup concept where duplicates from source can be prevented from loading into target table?
Source table
col1 | col2 | col3 | col4 | col5 | col6 | col7 | col8 | col | col9 | col10
Intermediate table (For SCD-2 identifying columns are col1, col2, col4)