postgresql 查看数据库,表,索引,表空间以及大小

客户要求用pgsql，所在服务器装了一下pgsql，我出了一个pgsql的分类，看这篇文章前，把这个分类下的文章都可以看一下，这是我熟悉pgsql的一套流程。以前搞过一次pgsql，很早了。

1,查看数据库

 playboy=> \l                       //\加上字母l,相当于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');    //查看playboy数据库的大小
  pg_database_size
 ------------------
           3637896
 (1 row)

 playboy=> select pg_database.datname, pg_database_size(pg_database.datname) AS size from pg_database;    //查看所有数据库的大小
   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的方式来查看数据库大小
  pg_size_pretty
 ----------------
  3553 kB
 (1 row)

2，查看多表

 playboy=> \dt                      //相当于mysql的，mysql> show tables;
         List of relations
  Schema | Name | Type  |  Owner
 --------+------+-------+---------
  public | test | table | playboy
 (1 row)

3，查看单表

 playboy=> \d test;                 //相当于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');   //查看表大小
  pg_relation_size
 ------------------
                 0
 (1 row)

 playboy=> select pg_size_pretty(pg_relation_size('test'));   //以KB，MB，GB的方式来查看表大小
  pg_size_pretty
 ----------------
  0 bytes
 (1 row)

 playboy=> select pg_size_pretty(pg_total_relation_size('test'));   //查看表的总大小，包括索引大小
  pg_size_pretty
 ----------------
  8192 bytes
 (1 row)

4，查看索引

 playboy=> \di                      //相当于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'));    //查看索大小
  pg_size_pretty
 ----------------
  8192 bytes
 (1 row)

5，查看表空间，以及大小

 playboy=> select spcname from pg_tablespace;         //查看所有表空间
   spcname
 ------------
  pg_default
  pg_global
 (2 rows)

 playboy=> select pg_size_pretty(pg_tablespace_size('pg_default'));   //查看表空间大小
  pg_size_pretty
 ----------------
  14 MB
 (1 row)