Hi Team, I am new to Snowflake, and started learning: question is 1.when I copy into from s3 bucket where file is kept and I am not knowing how many columns and column name then how to create in worksheet with column name as per my undertsanding we need to mention as col1, col2, col3 and if col exceeds it will filled with null later will do alter table, will this approach is correct? 2 question is in s3 bucket excel file have 10 columns but i need only few columns how to do?