nerdexam
Snowflake

COF-C02 · Question #51

Which of the following describes how clustering keys work in Snowflake?

The correct answer is B. Clustering keys sort the designated columns over time, without blocking DML operations. Snowflake clustering keys work through an asynchronous background process called Automatic Clustering. Over time, Snowflake reorganizes micro-partitions so that rows sharing similar clustering key values are co-located, improving pruning efficiency for range-based queries…

Snowflake Cloud Data Platform Features and Architecture

Question

Which of the following describes how clustering keys work in Snowflake?

Options

  • AClustering keys update the micro-partitions in place with a full sort, and impact the DML
  • BClustering keys sort the designated columns over time, without blocking DML operations
  • CClustering keys create a distributed, parallel data structure of pointers to a table's rows and
  • DClustering keys establish a hashed key on each node of a virtual warehouse to optimize joins at

How the community answered

(36 responses)
  • A
    3% (1)
  • B
    86% (31)
  • C
    8% (3)
  • D
    3% (1)

Explanation

Snowflake clustering keys work through an asynchronous background process called Automatic Clustering. Over time, Snowflake reorganizes micro-partitions so that rows sharing similar clustering key values are co-located, improving pruning efficiency for range-based queries. Critically, this process runs in the background and does not block or impact concurrent DML operations (inserts, updates, deletes). Option A is wrong because micro-partitions are immutable - they are never updated in place; new micro-partitions are written and old ones retired. Option C describes an index structure, which Snowflake does not use. Option D describes hash-based join optimization at the warehouse level, which is unrelated to clustering.

Topics

#Clustering Keys#Automatic Clustering#Performance Optimization#Data Organization

Community Discussion

No community discussion yet for this question.

Full COF-C02 Practice