Apply Clustering and Materialized Views ARA-C01 Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   How does Snowflake keep a materialized view up to date when the base table changes?

   • AIt requires the user to run REFRESH MATERIALIZED VIEW manually
   • BIt only updates the view when the base table is fully reloaded
   • CIt automatically refreshes the view in the background
   • DIt recreates the view from scratch each time the base table is queried
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2. 17foundation · easy

   How does Snowflake handle reclustering of a table that has a clustering key defined?

   • AIt requires the user to manually run ALTER TABLE ... RECLUSTER after every load
   • BIt only reclusters when the table is queried
   • CIt automatically reclusters the table in the background as needed
   • DIt never reclusters automatically; users must use the CLUSTER BY clause
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4. 18foundation · easy

   What condition must be met for Snowflake to automatically rewrite a query to use a materialized view?

   • AThe query must explicitly reference the materialized view name
   • BThe materialized view must be created with the FORCE option
   • CThe query must use the same column aliases as the materialized view
   • DThe query must be semantically equivalent to the materialized view's definition
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5. 19application · medium

   A materialized view `mv_orders` is defined as `SELECT customer_id, SUM(amount) FROM orders GROUP BY customer_id`. A user runs a query that filters on `customer_id` and `order_date`. Will Snowflake rewrite this query to use the materialized view?

   • AYes, because the materialized view contains the customer_id and SUM(amount)
   • BNo, because the query includes a column not in the materialized view
   • CNo, because materialized views are never used for queries with filters
   • DYes, because Snowflake can join the materialized view with the base table
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6. 20foundation · easy

   When is clustering a better choice than a materialized view?

   • AWhen the table is small and queries are simple point lookups
   • BWhen queries filter on a column that is not used in aggregations
   • CWhen queries perform complex joins that are run infrequently
   • DWhen the table is updated very frequently with small inserts
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