What are the distinct capacity each catalog can have?
select distinct capacity from catalog_contents
Which one is the most common?
select capacity from catalog_contents group by capacity order by count(*) desc limit 1
Which one is the smallest?
select capacity from catalog_contents order by capacity asc limit 1
What is the name of a catalog product that has this?
select catalog_entry_name from catalog_contents order by capacity asc limit 1