查看数据库的大小
select pg_database_size('test');
select pg_size_pretty(pg_database_size('test');

查看单索引大小

elect pg_relation_size('idx_id');
select pg_size_pretty(pg_relation_size('idx_id');

查看表中所有索引大小

select pg_indexes_size('user');

select pg_size_pretty(pg_indexes_size('user'));

使用pg_table_size() 函数查看

select pg_table_size('user');

select pg_size_pretty(pg_table_size('user'));

查看表大小同pg_table_size（）

select pg_relation_size('user');

select pg_size_pretty(pg_relation_size('user'));

查看表总大小

select pg_total_relation_size('user');
select pg_size_pretty(pg_total_relation_size('user'));

参考

https://www.cnblogs.com/mchina/archive/2013/04/19/3028573.html