What is the structure of the document with the least number of accesses?
create table document_structures (document_structure_description varchar, document_structure_code varchar, PRIMARY KEY (document_structure_description)); create table documents (document_structure_code varchar, PRIMARY KEY (document_structure_code))
select t2.document_structure_description from documents as t1 join document_structures as t2 on t1.document_structure_code = t2.document_structure_code group by t1.document_structure_code order by count(*) desc limit 1