PostgreSQL 统计信息函数

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MCV列表中的所有项目。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。