フリー問題

問題文

A retail team sets the number of shuffle partitions to a large value so that a peak-season job has enough parallelism. On ordinary days the same job now shows thousands of attempts that each finish in a few milliseconds. The adaptive framework is on. What is its merging of neighboring partitions for?

選択肢

1. The adaptive framework merges neighboring shuffle partitions to avoid numerous small tasks in the following stage.
2. The adaptive framework merges neighboring shuffle partitions to avoid wide column scans in the following stage.
3. The adaptive framework merges neighboring shuffle partitions to avoid sorted merge joins in the following stage.
4. The adaptive framework merges neighboring shuffle partitions to avoid extra reader copies in the following stage.