COF-C02 · Question #218
Which statement describes pruning?
The correct answer is A. The filtering or disregarding of micro-partitions that are not needed to return a query. Pruning is Snowflake's mechanism of skipping (filtering out) micro-partitions that are not relevant to a query's WHERE clause or join conditions. Snowflake stores min/max metadata for each micro-partition, and the query optimizer uses this metadata to eliminate partitions that…
Question
Which statement describes pruning?
Options
- AThe filtering or disregarding of micro-partitions that are not needed to return a query.
- BThe return of micro-partitions values that overlap with each other to reduce a query's runtime.
- CA service that is handled by the Snowflake Cloud Services layer to optimize caching.
- DThe ability to allow the result of a query to be accessed as if it were a table.
How the community answered
(66 responses)- A88% (58)
- B8% (5)
- C2% (1)
- D3% (2)
Explanation
Pruning is Snowflake's mechanism of skipping (filtering out) micro-partitions that are not relevant to a query's WHERE clause or join conditions. Snowflake stores min/max metadata for each micro-partition, and the query optimizer uses this metadata to eliminate partitions that cannot contain matching rows-avoiding unnecessary I/O and speeding up queries. Option B is the opposite of pruning (overlap between partitions reduces its effectiveness). Option C describes caching, not pruning. Option D describes a materialized view or CTE, not pruning.
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