問題文
A dataflow needs to keep only a subset of columns, add rows from another stream of the same shape, and update existing dataset rows. Which nodes correspond to these?
選択肢
- filter to add rows from another stream, dim2mea to keep columns, and flatten to update rows each night.
- computeExpression for all three, because it alone can restructure the stream and its rows in the dataset.
- sliceDataset to keep/drop columns, append to add same-shaped rows and update to modify existing rows.
- augment for all three, because it can slice, append, and update at once. One node would cover column selection, appending, and updates, leaving the others nothing to do.