轉載自部落格

1,檢視資料庫

playboy=> \l                       //\加上字母l,相當於mysql的，mysql> show databases;
        List of databases
   Name    |  Owner   | Encoding
-----------+----------+----------
 playboy   | postgres | UTF8
 postgres  | postgres | UTF8
 template0 | postgres | UTF8
 template1 | postgres | UTF8

playboy=> select pg_database_size('playboy');    //檢視playboy資料庫的大小
 pg_database_size
------------------
          3637896
(1 row)

playboy=> select pg_database.datname, pg_database_size(pg_database.datname) AS size from pg_database;    //檢視所有資料庫的大小
  datname  |  size
-----------+---------
 postgres  | 3621512
 playboy   | 3637896
 template1 | 3563524
 template0 | 3563524
(4 rows)

playboy=> select pg_size_pretty(pg_database_size('playboy'));      //以KB，MB，GB的方式來檢視資料庫大小
 pg_size_pretty
----------------
 3553 kB
(1 row)
 

playboy=> \d test;                 //相當於mysql的，mysql> desc test;
            Table "public.test"
 Column |         Type          | Modifiers
--------+-----------------------+-----------
 id     | integer               | not null
 name   | character varying(32) |
Indexes: "playboy_id_pk" PRIMARY KEY, btree (id)

playboy=> select pg_relation_size('test');   //查看錶大小
 pg_relation_size
------------------
                0
(1 row)

playboy=> select pg_size_pretty(pg_relation_size('test'));   //以KB，MB，GB的方式來查看錶大小
 pg_size_pretty
----------------
 0 bytes
(1 row)

playboy=> select pg_size_pretty(pg_total_relation_size('test'));   //查看錶的總大小，包括索引大小
 pg_size_pretty
----------------
 8192 bytes
(1 row)
 

playboy=> \d test;                 //相當於mysql的，mysql> desc test;
            Table "public.test"
 Column |         Type          | Modifiers
--------+-----------------------+-----------
 id     | integer               | not null
 name   | character varying(32) |
Indexes: "playboy_id_pk" PRIMARY KEY, btree (id)

playboy=> select pg_relation_size('test');   //查看錶大小
 pg_relation_size
------------------
                0
(1 row)

playboy=> select pg_size_pretty(pg_relation_size('test'));   //以KB，MB，GB的方式來查看錶大小
 pg_size_pretty
----------------
 0 bytes
(1 row)

playboy=> select pg_size_pretty(pg_total_relation_size('test'));   //查看錶的總大小，包括索引大小
 pg_size_pretty
----------------
 8192 bytes
(1 row)
 

playboy=> \di                      //相當於mysql的，mysql> show index from test;
                List of relations
 Schema |     Name      | Type  |  Owner  | Table
--------+---------------+-------+---------+-------
 public | playboy_id_pk | index | playboy | test
(1 row)

playboy=> select pg_size_pretty(pg_relation_size('playboy_id_pk'));    //檢視索大小
 pg_size_pretty
----------------
 8192 bytes
(1 row)

playboy=> select spcname from pg_tablespace;         //檢視所有表空間
  spcname
------------
 pg_default
 pg_global
(2 rows)

playboy=> select pg_size_pretty(pg_tablespace_size('pg_default'));   //查看錶空間大小
 pg_size_pretty
----------------
 14 MB
(1 row)