How many different attributes are there?
select count(*) from attribute_definitions
What is the id of the one that is used in the most catalog content entries?
select attribute_id from catalog_contents_additional_attributes group by attribute_id order by count(*) desc limit 1
Which catalog content entries use this attribute value?
select * from catalog_contents as t1 join catalog_contents_additional_attributes as t2 on t1.catalog_entry_id = t2.catalog_entry_id where t2.attribute_id = (select attribute_id from catalog_contents_additional_attributes group by attribute_id order by count(*) desc limit 1)
Show me just their catalog entry names?
select t1.catalog_entry_name from catalog_contents as t1 join catalog_contents_additional_attributes as t2 on t1.catalog_entry_id = t2.catalog_entry_id where t2.attribute_id = (select attribute_id from catalog_contents_additional_attributes group by attribute_id order by count(*) desc limit 1)