D is the correct answer. Snowflake makes use of clustering on tables. Users can utilize cluster key to enhance query performance (partition pruning) on large tables. Lesser the number of joins between several tables = better performance in general.

The correct answer is D. Use a smaller number of larger tables rather than a larger number of smaller tables. Here are some of the reasons why using a smaller number of larger tables can improve query performance in Snowflake: Reduced data movement: When you join multiple tables, Snowflake needs to move data between the tables. This can be a bottleneck, especially if the tables are large. Using a smaller number of larger tables can reduce the amount of data that needs to be moved, which can improve performance. Improved caching: Snowflake caches data in memory. When you use a smaller number of larger tables, the data is more likely to be cached in memory, which can also improve performance. Simplified query planning: Snowflake's query planner is more efficient when it has to plan queries for a smaller number of tables. This can also improve performance.

D this time

This because subqueries will cache their result and it can be reused