postgres 查看数据表和索引的大小

    *  查看所有public schema里面索引大小，大到小的顺序排列 

  select indexrelname, pg_size_pretty(pg_relation_size(indexrelname)) 
    from pg_stat_user_indexes where 
         schemaname = 'public' order by pg_relation_size(indexrelname) desc; 

    * 查看所有public schema里面表的大小，从大到小顺序排里 

  select relname, pg_size_pretty(pg_relation_size(relname)) 
    from pg_stat_user_tables where 
         schemaname = 'public' order by pg_relation_size(relname) desc; 

查看单个表的大小： 
    *  pg_relation_size('关系名') - 查看关系大小 

   GZ125=# select pg_relation_size('contact'); 
   GZ125=# select pg_size_pretty(pg_relation_size('contact'));