DEA-C02 Performance Optimization Practice Question
A user is experiencing 'Data Spilling' in a query that performs a complex window function over a very large dataset. What is the most likely reason this is occurring and how should it be addressed?
⚠ Common exam trap
Candidates often think that scaling out (adding clusters) fixes data spilling caused by large window functions, confusing concurrency handling with the need for more memory per node.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The query requires a large sort buffer; scale up the warehouse.
Window functions require sorting data based on the partition and order keys specified in the query. If the dataset is too large for the memory assigned to the warehouse nodes, Snowflake will spill the sorting process to local disk or remote storage. Increasing the warehouse size allocates more memory per node, which can accommodate larger sort buffers, thereby reducing or eliminating the need for disk spilling during the window function operation.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The query is missing a filter, and scaling out will fix it.
Why it's wrong here
Scaling out (adding clusters) does not increase memory per query; it only increases concurrency capacity. If a single query is spilling, adding more clusters will not provide the extra memory needed to perform the sort in RAM. Scaling up (increasing warehouse size) is required instead.
- ✓
The query requires a large sort buffer; scale up the warehouse.
Why this is correct
Window functions perform memory-intensive operations like sorting. If the dataset exceeds the memory capacity of the current warehouse size, spilling occurs. Scaling up to a larger warehouse increases the memory available to the individual nodes, allowing the sort operation to complete in RAM without disk involvement.
- ✗
The table is not clustered, which causes excessive scanning.
Why it's wrong here
Clustering helps reduce the number of partitions scanned, which improves performance, but it does not directly manage the memory required for the internal sorting process of a window function. Even with perfect clustering, a large window function operation could still cause spilling if memory is insufficient.
- ✗
The query needs a dedicated 'Snowpark-optimized' warehouse.
Why it's wrong here
While Snowpark-optimized warehouses are useful for memory-intensive Python or Java code, standard SQL window functions can be optimized by simply using a larger standard warehouse. A Snowpark-optimized warehouse is an expensive choice that is generally overkill for pure SQL window function operations.
About these practice questions
This DEA-C02 question is part of Courseiva's 229-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Snowflake exam blueprint
This DEA-C02 practice question is part of Courseiva's free Snowflake certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DEA-C02 exam.