postgresql学习笔记--基础篇 -psql工具

--创建用户
CREATE ROLE pguser WITH ENCRYPTED PASSWORD 'pguser';
--创建表空间目录
mkdir -p /database/pg10/pg_tbs/tbs_mydb
--创建表空间
CREATE TABLESPACE tbs_mydb OWNER pguser LOCATION '/database/pg10/pg_tbs/tbs_mydb';
--创建数据库
CREATE DATABSE mydb WITH OWNER = pguser TEMPLATE=template0 ENCODING='UTF8' TABLESPACE=tbs_mydb;
--赋权
GRANT ALL ON DATABASE mydb TO pguser WITH GRANT OPTION;
GRANT ALL ON TABLESPACE tbs_mydb TO pguser;

1. psql 元命令介绍

1.1 \l 列出所有数据库列表

postgres=# \l
                                  List of databases
   Name    |  Owner   | Encoding |  Collation  |    Ctype    |   Access privileges
-----------+----------+----------+-------------+-------------+-----------------------
 ambari    | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =Tc/postgres
                                                             : postgres=CTc/postgres
                                                             : ambari=CTc/postgres
 ambarirca | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =Tc/postgres
                                                             : postgres=CTc/postgres
                                                             : mapred=CTc/postgres
 mydb      | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 |
 postgres  | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 |
 template0 | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =c/postgres
                                                             : postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.UTF-8 | en_US.UTF-8 | =c/postgres
                                                             : postgres=CTc/postgres
(6 rows)

1.2 、\db 查看表空间列表

postgres=# \db
       List of tablespaces
    Name    |  Owner   | Location
------------+----------+----------
 pg_default | postgres |
 pg_global  | postgres |
(2 rows)

1.3 \d查看表定义

postgres=# \dt
                  List of relations
 Schema |           Name           | Type  |  Owner
--------+--------------------------+-------+----------
 public | cloud_sql_static         | table | postgres
 public | cloud_subscriber_devices | table | postgres
 public | cloud_subscribers        | table | postgres
 public | cloud_table_static       | table | postgres
 public | sxacc-device-types       | table | postgres
 public | sxacc-devices            | table | postgres
(6 rows)

postgres=# \d cloud_table_static
             Table "public.cloud_table_static"
       Column        |           Type           | Modifiers
---------------------+--------------------------+-----------
 relname             | character varying(255)   |
 seq_scan            | bigint                   |
 seq_tup_read        | bigint                   |
 idx_scan            | bigint                   |
 idx_tup_fetch       | bigint                   |
 n_tup_ins           | bigint                   |
 n_tup_upd           | bigint                   |
 n_tup_del           | bigint                   |
 n_tup_hot_upd       | bigint                   |
 n_live_tup          | bigint                   |
 n_dead_tup          | bigint                   |
 n_mod_since_analyze | bigint                   |
 last_vacuum         | timestamp with time zone |
 last_autovacuum     | timestamp with time zone |
 last_analyze        | timestamp with time zone |
 last_autoanalyze    | timestamp with time zone |
 vacuum_count        | bigint                   |
 autovacuum_count    | bigint                   |
 analyze_count       | bigint                   |
 autoanalyze_count   | bigint                   |
 import_date         | timestamp with time zone |

postgres=#

 1.4 查看表/索引占用空间大小

给测试表test插入500万数据：

postgres=# create table test(id int primary key, name varchar(100));
CREATE TABLE
postgres=# insert into test(id,name) select n,n||'_francs' from generate_series(1,5000000) n;
INSERT 0 5000000
postgres=# \di+ test_pkey
                          List of relations
 Schema |   Name    | Type  |  Owner   | Table |  Size  | Description
--------+-----------+-------+----------+-------+--------+-------------
 public | test_pkey | index | postgres | test  | 107 MB |
(1 row)

postgres=# \dt+ test
                    List of relations
 Schema | Name | Type  |  Owner   |  Size  | Description
--------+------+-------+----------+--------+-------------
 public | test | table | postgres | 249 MB |
(1 row)

1.5 \sf 查看函数代码

mydb#\sf random_range
CREATE OR REPLACE FUNCTION pguser.random_range(integer,integer)
     RETURN integer
     LANGUAGE sql
AS $function$
     SELECT ($1 + FLOOR(($2-$1 +1 )* random()))::int4;
     $function$

上述\sf命令后面可以只接函数的名称，或者函数名称及输入参数类型，例如random_range(integer,integer)，Postgres支持名称相同但输入参数类型不同的函数，如果有同名函数，\sf 必须指定参数类型。 

1.6 \x 设置查询结果输出

postgres=# \x
Expanded display is on.
postgres=# select * from test limit 1;
-[ RECORD 1 ]--
id   | 1
name | 1_francs

1.7 -E 获取元命令对应的SQL代码

postgres:~$ psql -E
psql (9.5.14)
Type "help" for help.

postgres=# \db
********* QUERY **********
SELECT spcname AS "Name",
  pg_catalog.pg_get_userbyid(spcowner) AS "Owner",
  pg_catalog.pg_tablespace_location(oid) AS "Location"
FROM pg_catalog.pg_tablespace
ORDER BY 1;
**************************

       List of tablespaces
    Name    |  Owner   | Location
------------+----------+----------
 pg_default | postgres |
 pg_global  | postgres |
(2 rows)

postgres=#