1、检查数据库版本：
postgres=# select version();
version
--------------------------------------------------------------------------------
-----------------------------
Postgresql 9.4.2 on x86_64-redhat-linux-gnu,compiled by gcc (GCC) 5.1.1 201504
22 (Red Hat 5.1.1-1),64-bit
(1 行记录)
2、查看数据库启动时间：
postgres=# select pg_postmaster_start_time(); pg_postmaster_start_time ------------------------------- 2015-06-12 19:06:23.031591+08
截至当前时间，运行了多长时间：
postgres=# select current_timestamp - pg_postmaster_start_time() as uptime;
uptime
-----------------
02:34:13.631323
postgres=# select date_trunc('second',current_timestamp-pg_postmaster_start_time()) as uptime;
uptime
----------
02:36:10
3、列出当前所有数据库：
bash-4.3$ psql -l 资料库列表 名称 | 拥有者 | 字元编码 | 校对规则 | Ctype | 存取权限 -----------+----------+----------+-------------+-------------+----------------------- postgres | postgres | UTF8 | zh_CN.UTF-8 | zh_CN.UTF-8 | template0 | postgres | UTF8 | zh_CN.UTF-8 | zh_CN.UTF-8 | =c/postgres + | | | | | postgres=CTc/postgres template1 | postgres | UTF8 | zh_CN.UTF-8 | zh_CN.UTF-8 | =c/postgres + | | | | | postgres=CTc/postgres (3 行记录)
或
ostgres=# select datname from pg_database; datname ----------- template1 template0 postgres (3 行记录)
4、查看数据库文件大小
postgres=# select pg_database_size(current_database());
pg_database_size
------------------
6999828
上面是当前数据库
postgres=# select current_database(); current_database ------------------ postgres
或者所有数据库文件大小：
postgres=# select sum(pg_database_size(datname)) from pg_database; sum ---------- 20738844 (1 行记录)
