Performance Concepts: Query Optimization Quiz

Question 1

What is the minimum Snowflake edition with the materialized view feature?

Answer 1

Enterprise

Question 2

What is the maximum number of tables a materialized view can reference in it’s query definition?

Answer 2

1

Question 3

Which definition best describes natural clustering? Choose one correct value.
- Natural clustering describes the distribution of data among micro-partitions
- Natural clustering describes how large micro-partitions are
- Natural clustering describes how frequently a table is populated
- Natural clustering describes how many times a value in a micro-partition appears

Answer 3

Natural clustering describes the distribution of data among micro-partitions

Question 4

Which piece of clustering metadata does Snowflake not maintain for micro-partitions? Choose one correct value.
- Total number of micro-partitions
- Average number of overlapping micro-partitions
- Depth of overlapping micro-partitions
- Average overlapping micro-partitions across tables

Answer 4

Average overlapping micro-partitions across tables

Question 5

It’s possible to specify two columns (or expressions) in the system function, ‘clustering information’, such as in the following example select query: SELECT system$clustering_information(‘table’, ‘(col1,col3)’). True or false?

Answer 5

True

Question 6

Automatic clustering is recommended for tables larger than _______.

Answer 6

1 TB

Question 7

Snowflake supports specifying one or more table columns/expressions on a table as a clustering key. True or false?

Answer 7

True

Question 8

Which best describes what the search optimization service does? Choose one correct value.
- The search optimization service allows one account to share data securely with another account
- The search optimization service allows users to selectively mask data at query runtime
- The search optimization service allows users to improve the performance of selective point lookup queries
- The search optimization service allows users to search globally across a Snowflake account and it’s data for a specific record

Answer 8

The search optimization service allows users to improve the performance of selective point lookup queries

Question 9

The results of a query are cached for minimum of which duration?

Answer 9

24 hours

Question 10

The larger the virtual warehouse the larger the local cache. True or false?

Answer 10

True