The Merge operator is considered a DML (Data Manipulation Language) operator in Snowflake. DML operators are used to modify data in tables, and the Merge operator specifically allows for conditional updates, inserts, or deletes in a target table based on the results of a join with a source table.
References:
* Snowflake Documentation: Query Profile Overview
* Snowflake Documentation: MERGE Statement

To change the existing file format type from CSV to JSON, the recommended way is to use the ALTER FILE FORMAT command with the SET TYPE=JSON clause. This alters the file format specification to use JSON instead of CSV. Reference: Based on my internal knowledge as of 2021.

Snowflake credits are used to pay for the consumption of resources on Snowflake. A Snowflake credit is a unit of measure, and it is consumed only when a customer is using resources, such as when a virtual warehouse is running, the cloud services layer is performing work, or serverless features are used.
https://docs.snowflake.com/en/user-guide/what-are-credits.html

In a regular schema within Snowflake, the object owner has the privilege to grant object privileges. The object owner is typically the role that created the object or to whom the ownership of the object has been transferred78.
Reference = [COF-C02] SnowPro Core Certification Exam Study Guide

Snowflake recommends creating separate warehouses for each workload to resolve performance issues caused by shared virtual warehouses. This ensures that the resources are not being overutilized by one user's activities, thereby affecting the performance of another user's activities4.