SELECT template, COUNT(*) FROM iavz_site_content GROUP BY template;
Сколько раз используется какой TV параметр
SELECT tmplvarid, COUNT(*) FROM modx_site_tmplvar_contentvalues GROUP BY tmplvarid;
SELECT template, COUNT(*) FROM iavz_site_content GROUP BY template;
SELECT tmplvarid, COUNT(*) FROM modx_site_tmplvar_contentvalues GROUP BY tmplvarid;