pg_mcv_list_items ( pg_mcv_list ) → setof record

pg_mcv_list_items 返回一个记录集，描述存储在多列中的所有项目MCV列表。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 列中获取。