Append is used to combine datasets with the same structure one on top of the other. Say, for example, that you have data for different months or years in different datasets and you need to combine them into a single dataset.
In this option select the datasets you want to append directly and variables that you want to include. Make sure to the datasets to ensure that they have the same structure. Additionally, you can select how duplicates should be handled in the append process.
Another way to append dataset is fetch and modify data before append. Here are the steps you can follow:
1- In the "fetch" step, you need to select the dataset that you want to data from.
2- In the "Append Dataset" step, you can choose how to drop duplicate records. You have several options: Keep the first occurrence of a duplicate, or keep the last occurrence of a duplicate, or drop all duplicates.