The Table_Comparison transform compares a dataset generated inside a dataflow to a target table dataset and changes the statuses of data set rows to different types according to the conditions specified in the Table_Comparison transform.
Data Services uses primary key values for the row comparison and marks the passing row accordingly as: an insert row, which does not exist in the target table yet; an update row, the row for which primary key values exist in the target table but whose non-primary key fields (or comparison fields) have different values; and finally, a delete row (when the target dataset has rows with primary key values that do not exist in the source data set generated inside a dataflow). In some way, Table_Comparison does exactly the same thing as Map_Operation: it changes the row type of passing rows from normal to insert, update, or delete. The difference is that it does it in a smart way—after comparing the dataset to the target table...