ACE Question 97

Community Discussion

Written by other learners. Comments can disagree with the marked answer — check the official documentation when in doubt.

• Chose C1

  If the primary key is monotonically increasing (e.g., an incrementing sequence), all new rows are written to the same split. This causes the split to become a hotspot, leading to increased read and write latency because all operations are concentrated on a single node.

• Chose B2

  Why B: To improve read performance, we should add a secondary index on the primary key. Since we know that this table is accessed only by the primary key, this would optimize read operations. Why not C: Monotonically increasing values might create a hotspot, but this would primarily affect write operations. In fact, lookups would be easier with sequential values compared to a UUID. Additionally, it is not mentioned that users are only reading the last inserted data, which would create a read hotspot. Why not D: This approach could work, but since the table is accessed only by the primary key, there's no need to add additional fields to the index. Why not A: The profile_picture field should not significantly affect read performance.

• 2

  oh, just found that primary key is automatically indexed by default... so I would vote for A then, hahaha