pg_mcv_list_items ( pg_mcv_list ) → setof record

pg_mcv_list_items 返回一组记录，描述存储在多列列表中的所有项。MCV它返回以下列：

pg_mcv_list_items 函数可以这样使用：

SELECT m.* FROM pg_statistic_ext join pg_statistic_ext_data on (oid = stxoid),
                pg_mcv_list_items(stxdmcv) m WHERE stxname = 'stts';

pg_mcv_list 类型的值只能从 pg_statistic_ext_data.stxdmcv 列获取。