Snowflake Certification Practice Test

What indicates better efficiency in querying data within Snowflake?

1. A high ratio of scanned data to selected data

2. A low ratio of scanned data to selected data

3. Having minimal partitions

4. A ratio of 1:1

The correct answer is: A high ratio of scanned data to selected data

The concept of efficiency in querying data within Snowflake revolves around the balance between the amount of data that is scanned and the data that is actually selected or returned by the query. A low ratio of scanned data to selected data indicates that the query is effectively filtering out unnecessary information and is retrieving only the relevant data. This is a key factor in optimizing performance and reducing costs. When the ratio of scanned data is low compared to the selected data, it signifies that the query is efficient in its operations. It means that the database engine has to process less data to retrieve the desired results, leading to faster execution times and lower compute costs. Essentially, an efficient query minimizes the workload on the Snowflake infrastructure, thereby enhancing overall performance. In contrast, a high ratio of scanned data to selected data suggests that a significant amount of data is being read from the storage but only a small subset is actually needed, which can lead to increased costs and longer query runtimes. Therefore, for optimal query performance in Snowflake, aiming for a low ratio of scanned data to selected data is key to achieving efficiency.