The billable compute time includes the time the warehouse is running queries plus the auto-suspend time after the last query if the warehouse is not manually suspended. In this scenario, the warehouse runs for 3 minutes, suspends after 10 minutes of inactivity, resumes for a 10-second query, and then is manually suspended. The total billable time is the sum of the initial 3 minutes, the 10 minutes of auto-suspend time, and the brief period for the 10-second query, which is rounded up to the next full minute due to Snowflake's billing practices. Reference: [COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake's access control framework utilizes a combination of Discretionary Access Control (DAC) and Role-based Access Control (RBAC). DAC in Snowflake allows the object owner to grant access privileges to other roles. RBAC involves assigning roles to users and then granting privileges to those roles. Through roles, Snowflake manages which users have access to specific objects and what actions they can perform, which is central to security and governance in the Snowflake environment.
Reference: Snowflake Documentation on Access Control,

To delete staged files from a Snowflake stage, you can specify the PURGE option in the COPY INTO <table> command, which will automatically delete the files after they have been successfully loaded. Additionally, you can use the REMOVE command after the load completes to manually delete the files from the stage12.
Reference = DROP STAGE, REMOVE

Snowflake supports semi-structured data types that can store complex data structures within a single column. The VARIANT data type can hold structured and semi-structured data formats such as JSON, Avro, ORC, Parquet, and XML. The ARRAY data type is also used for semi-structured data and can store an ordered list of elements. These data types enable users to work with semi-structured data directly in Snowflake without needing to flatten the data into a relational schema first.
Reference: Snowflake Documentation on Semi-Structured Data Types

The WAIT_FOR_COMPLETION = TRUE parameter in an ALTER WAREHOUSE command ensures that the command does not return until the warehouse has completed resizing. This means that the command will wait until all the necessary compute resources have been provisioned and the warehouse size has been changed. Reference: [COF-C02] SnowPro Core Certification Exam Study Guide