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)