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Snowflake

DEA-C02 · Question #25

A Data Engineer is evaluating the performance of a query in a development environment. Based on the Query Profile, what are some performance tuning options the Engineer can use? (Choose two.)

The correct answer is A. Add a LIMIT to the ORDER BY if possible C. Move the query to a larger virtual warehouse. A is correct because adding a LIMIT to an ORDER BY allows Snowflake to stop sorting once the required rows are found, dramatically reducing one of the most expensive operations a query can perform - a full sort is unnecessary if only the top N rows are needed. C is correct…

Performance Optimization

Question

A Data Engineer is evaluating the performance of a query in a development environment. Based on the Query Profile, what are some performance tuning options the Engineer can use? (Choose two.)

Exhibit

DEA-C02 question #25 exhibit

Options

  • AAdd a LIMIT to the ORDER BY if possible
  • BUse a multi-cluster virtual warehouse with the scaling policy set to standard
  • CMove the query to a larger virtual warehouse
  • DCreate indexes to ensure sorted access to data
  • EIncrease the MAX_CLUSTER_COUNT

How the community answered

(24 responses)
  • A
    71% (17)
  • B
    8% (2)
  • D
    4% (1)
  • E
    17% (4)

Explanation

A is correct because adding a LIMIT to an ORDER BY allows Snowflake to stop sorting once the required rows are found, dramatically reducing one of the most expensive operations a query can perform - a full sort is unnecessary if only the top N rows are needed.

C is correct because a larger virtual warehouse provides more compute nodes, memory, and CPU, directly addressing resource bottlenecks visible in the Query Profile (e.g., spilling to disk, slow processing nodes).

B and E are wrong for the same reason: multi-cluster warehouses and MAX_CLUSTER_COUNT address concurrency - spinning up additional clusters to handle many simultaneous users - not the performance of a single query being tuned in dev.

D is wrong because Snowflake does not support traditional indexes; it uses micro-partition pruning and clustering keys instead. Indexes are a concept from row-store databases like PostgreSQL or MySQL.

Memory tip: Split the distractors into two buckets - "wrong database concept" (D = indexes don't exist in Snowflake) and "solves the wrong problem" (B and E = concurrency, not single-query speed). The correct answers follow the simple rule: reduce work (A) or add resources (C).

Topics

#Query Performance#Virtual Warehouses#SQL Optimization

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