1. A method for processing input data comprising: receiving multiple input rows to be loaded into a first structure; processing each input row of the multiple input rows to classify each input row as one of an insert row and an update row, wherein input duplicates are stored in the first structure and index entries for the input duplicates are stored in a second structure; and after the multiple input rows have been processed, automatically re-applying the input duplicates to the first structure; and processing the index entries stored in the second structure.