DEA-C02 · Question #102
A Data Engineer is trying to improve the performance of a long-running query by clustering the base table. What information from the output of the system function will verify CLUSTERING_INFORMATION…
The correct answer is D. The total number of constant micro-partitions in the table is low. Option D is correct because in Snowflake's SYSTEM$CLUSTERING_INFORMATION, a low count of constant micro-partitions - partitions where the clustering key's min and max values are identical - indicates the clustering process has successfully redistributed data so that partitions…
Question
Options
- AThe average number of overlapping micro-partitions in the table is high.
- BThe total number of constant micro-partitions in the table is high.
- CThe average overlap depth of each micro-partition in the table is high.
- DThe total number of constant micro-partitions in the table is low.
How the community answered
(56 responses)- A9% (5)
- B4% (2)
- C16% (9)
- D71% (40)
Explanation
Option D is correct because in Snowflake's SYSTEM$CLUSTERING_INFORMATION, a low count of constant micro-partitions - partitions where the clustering key's min and max values are identical - indicates the clustering process has successfully redistributed data so that partitions span meaningful, non-overlapping ranges of the clustering key rather than being fragmented into single-value chunks, which optimizes range-based query pruning.
Options A and C are both wrong for the same reason: high average overlapping micro-partitions (A) and high average overlap depth (C) are both symptoms of poor clustering, meaning Snowflake must scan more micro-partitions per query - exactly what clustering is meant to fix. You want these values low after clustering.
Option B is wrong because a high constant micro-partition count would signal excessive fragmentation - each partition holds only one distinct clustering key value - which means clustering reorganized the data too granularly rather than optimally grouping rows into prunable, range-bounded partitions.
Memory tip: Think of overlap as the enemy. After clustering, you want depth and overlaps to be LOW (like a neat stack of sorted cards with no interleaving). Constant partitions being LOW means the data is spread efficiently across ranges, not broken into countless single-value silos. When in doubt: low overlap + low constant = clustering success.
Topics
Community Discussion
No community discussion yet for this question.