postgresql查看数据库,表,索引,表空间以及大小

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)

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)

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)

查看索引

playboy=>
4000
\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)

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)