A batch transformation will transform batches of data. The default batch size are 100000 rows. The batch transformation function allows you to process and modify each batch of data. You can use the BatchSize property to choose a smaller batch size. The batch size must always be smaller than the max buffer size. The default batch size are 1000 rows per batch. The batch transformation is a partial blocking transformation - it will always need at least enough memory to store a whole batch.