Q&A for professional and enthusiast programmers
select t.id, count(t.tagName) as synonym_count, string_agg(TagSynonyms.SourceTagName, ',') as synonyms, t.tagName, concat('stackoverflow.com/tags/',t.tagName ,'/info') from tags t left join TagSynonyms on TagSynonyms.TargetTagName = t.tagName group by t.tagName, t.id order by count(t.tagName) desc