PostgreSQL 学习笔记013 —— PostgreSQL 常用命令（3）

查看数据库的启动时间

postgres=# select pg_postmaster_start_time();
   pg_postmaster_start_time
-------------------------------
 2023-01-02 10:39:31.176939+08
(1 row)

查看最后load配置文件时间

postgres=# select pg_conf_load_time();
       pg_conf_load_time
-------------------------------
 2023-01-02 10:39:30.506262+08
(1 row)

显示数据库当前时区和时间

postgres=# show timezone;
   TimeZone
---------------
 Asia/Shanghai
(1 row)

postgres=# select now();
              now
-------------------------------
 2023-01-02 20:55:31.156172+08
(1 row)

列出当前数据库下的数据表

-- \d或\d+(推荐)，\d+会额外输出表的注释

postgres=# \d
         List of relations
 Schema | Name  | Type  |  Owner
--------+-------+-------+----------
 public | test1 | table | postgres
(1 row)

列出指定表的所有字段

-- \d 表名或\d+ 表名(推荐)，\d+ 表名会额外输出字段的注释

postgres=# \d test1
               Table "public.test1"
 Column |  Type   | Collation | Nullable | Default
--------+---------+-----------+----------+---------
 id     | integer |           |          |

查看指定表的基本情况

postgres=# \d+ test1
                                          Table "public.test1"
 Column |  Type   | Collation | Nullable | Default | Storage | Compression | Stats target | Description
--------+---------+-----------+----------+---------+---------+-------------+--------------+-------------
 id     | integer |           |          |         | plain   |             |              |
Access method: heap

退出登录

postgres=# \q
[postgres@192 ~]$

Ctrl + D

查看所有用户

postgres=# select * from pg_roles;
          rolname          | rolsuper | rolinherit | rolcreaterole | rolcreatedb | rolcanlogin | rolreplication | rolconnlimit | rolpassword | rolvaliduntil | rolbypassrls | rolconfig | oid
---------------------------+----------+------------+---------------+-------------+-------------+----------------+--------------+-------------+---------------+--------------+-----------+------
 postgres                  | t        | t          | t             | t           | t           | t              |           -1 | ********    |               | t            |           |   10
 pg_database_owner         | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 6171
 pg_read_all_data          | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 6181
 pg_write_all_data         | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 6182
 pg_monitor                | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 3373
 pg_read_all_settings      | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 3374
 pg_read_all_stats         | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 3375
 pg_stat_scan_tables       | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 3377
 pg_read_server_files      | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 4569
 pg_write_server_files     | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 4570
 pg_execute_server_program | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 4571
 pg_signal_backend         | f        | t          | f             | f           | f           | f              |           -1 | ********    |               | f            |           | 4200
(12 rows)