postgres 表和库等信息大小统计

一 .数据库大小的统计

1.单个库查询

select pg_database_size('zybdb');

2.查询全部的库

 方法一：

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

方法二：

SELECT d.datname AS Name,  pg_catalog.pg_get_userbyid(d.datdba) AS Owner,
    CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')  THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))
        ELSE 'No Access'   END AS SIZE
FROM pg_catalog.pg_database d
    ORDER BY    CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')     THEN pg_catalog.pg_database_size(d.datname)    ELSE NULL  END DESC  

二 数据库表大小查询

全部表方法一：

SELECT
    table_schema || '.' || table_name AS table_full_name,
    pg_size_pretty(pg_total_relation_size('"' || table_schema || '"."' || table_name || '"')) AS size
FROM information_schema.tables WHERE table_schema='cas_it'
ORDER BY pg_total_relation_size('"' || table_schema || '"."' || table_name || '"') desc;

全部表方法二：

SELECT relname,pg_size_pretty(pg_relation_size(relid))
FROM pg_stat_user_tables WHERE schemaname='cas_it' ORDER BY pg_size_pretty(pg_relation_size(relid)) DESC

单个表方法一：

select pg_relation_size('cas_it.t4');

单个表方法二：

select pg_size_pretty(pg_total_relation_size('cas_it.t4'));

 

三 查询索引大小

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