pg统计磁盘占用大小

select 

    sum(t.size) 

from (

    SELECT 

          table_schema || '.' || table_name AS table_full_name

        , pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')AS size

    FROM information_schema.tables

    ORDER by pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') DESC

    ) t
;

SELECT 

      table_schema || '.' || table_name AS table_full_name

    , pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') AS size_bytes

    , pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')/1024/1024 as size_mb

    , pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')/1024/1024/1024 as size_gb

FROM information_schema.tables

ORDER by pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') DESC
;

select pg_database_size('xx');

select 
     pg_database.datname
    ,pg_database_size(pg_database.datname) AS size 
from pg_database;

select pg_relation_size('table_name');   --bytes

select pg_size_pretty(pg_relation_size('table_name'));  

select pg_size_pretty(pg_total_relation_size('table_name'));  

select pg_size_pretty(pg_relation_size('table_pkey')); 

select spcname from pg_tablespace; 

select pg_size_pretty(pg_tablespace_size('pg_default'));