In Snowflake, auto-scaling allows virtual warehouses to automatically start additional clusters to handle increasing query loads. The setting that triggers the immediate start of additional clusters when a warehouse is running in auto-scale mode is:A. MAX_CLUSTER_COUNT is increased and new_max_clusters is greater than running_clusters: When the maximum number of clusters (MAX_CLUSTER_COUNT) is increased and the new maximum is higher than the number of clusters currently running (running_clusters), additional clusters will start immediately if required by the workload. This configuration ensures that performance scales with demand by allowing more compute resources to be provisioned as needed.
This behavior is designed to maintain performance by dynamically adjusting the compute resources without manual intervention, ensuring that queries are executed with minimal delay, even under varying workloads. It aligns with the principles of elasticity and scalability in cloud computing, particularly within Snowflake's architecture.

The Information Schema and Account Usage Share in Snowflake provide metadata and historical usage data for various objects within a Snowflake account. Specifically, they offer storage information for Tables, Databases, and Internal Stages. These schemas contain views and table functions that allow users to query object metadata and usage metrics, such as the amount of data stored and historical activity.
* Tables: The storage information includes data on the daily average amount of data in database tables.
* Databases: For databases, the storage usage is calculated based on all the data contained within the database, including tables and stages.
* Internal Stages: Internal stages are locations within Snowflake for temporarily storing data, and their storage usage is also tracked.
References: The information is verified according to the SnowPro Core Certification Study Guide and Snowflake documentation

Clustering is a technique used in Snowflake to improve the performance of queries. It involves organizing the data in a table into micro-partitions based on the values of one or more columns. This organization allows Snowflake to efficiently prune non-relevant micro-partitions during a query, which reduces the amount of data scanned and improves query performance.
References:
* [COF-C02] SnowPro Core Certification Exam Study Guide
* Snowflake Documentation on Clustering