centos7下postgresql数据库安装及配置

1、安装

#yum install -y postgresql-server

2、postgresql数据库初始化

#service postgresql initdb

3、启动postgresql服务

#systemctl start postgresql
#systemctl enable postgresql

4、查看postgresql状态

#netstat -tlunp|grep 5432
#ss -tlunp|grep 5432

5、连接postgresql数据库

想连接到数据库，需要切换到postgres用户（默认情况下，安装postgresql时会自动生成），使用psql连接到数据库中，在该用户下连接数据库，是不需要密码的。

#查看生成的用户
# tail -1 /etc/passwd
postgres:x:26:26:PostgreSQL Server:/var/lib/pgsql:/bin/bash
#切换用户，登录postgresql
[root@centos7 data]# su - postgres
Last login: Thu Oct 24 16:06:34 CST 2019 on pts/1
-bash-4.2$ psql		#使用psql登录数据库
psql (9.2.24)
Type "help" for help.

postgres=# \l		#列出所有数据库，相当于show databases;
                             List of databases
   Name    |  Owner   | Encoding  | Collate | Ctype |   Access privileges
-----------+----------+-----------+---------+-------+-----------------------
 postgres  | postgres | SQL_ASCII | C       | C     |
 template0 | postgres | SQL_ASCII | C       | C     | =c/postgres          +
           |          |           |         |       | postgres=CTc/postgres
 template1 | postgres | SQL_ASCII | C       | C     | =c/postgres          +
           |          |           |         |       | postgres=CTc/postgres
(3 rows)
postgres=# \q		#退出数据库
-bash-4.2$

6、postgresql的简单配置

postgresql数据库的配置主要是通过修改数据目录下的postgresql.conf文件来实现的

# ll /var/lib/pgsql/data/  #yum安装时路径
total 48
drwx------. 5 postgres postgres    41 Oct 24 15:49 base
drwx------. 2 postgres postgres  4096 Oct 24 15:50 global
drwx------. 2 postgres postgres    18 Oct 24 15:49 pg_clog
-rw-------. 1 postgres postgres  4232 Oct 24 15:49 pg_hba.conf
-rw-------. 1 postgres postgres  1636 Oct 24 15:49 pg_ident.conf
drwx------. 2 postgres postgres    32 Oct 24 15:49 pg_log
drwx------. 4 postgres postgres    36 Oct 24 15:49 pg_multixact
drwx------. 2 postgres postgres    18 Oct 24 15:50 pg_notify
drwx------. 2 postgres postgres     6 Oct 24 15:49 pg_serial
drwx------. 2 postgres postgres     6 Oct 24 15:49 pg_snapshots
drwx------. 2 postgres postgres    25 Oct 24 16:26 pg_stat_tmp
drwx------. 2 postgres postgres    18 Oct 24 15:49 pg_subtrans
drwx------. 2 postgres postgres     6 Oct 24 15:49 pg_tblspc
drwx------. 2 postgres postgres     6 Oct 24 15:49 pg_twophase
-rw-------. 1 postgres postgres     4 Oct 24 15:49 PG_VERSION
drwx------. 3 postgres postgres    60 Oct 24 15:49 pg_xlog
-rw-------. 1 postgres postgres 19805 Oct 24 15:49 postgresql.conf
-rw-------. 1 postgres postgres    57 Oct 24 15:50 postmaster.opts
-rw-------. 1 postgres postgres    92 Oct 24 15:50 postmaster.pid

7、修改监听的Ip和端口

#vim /var/lib/pgsql/data/postgresql.conf
59 #listen_addresses = 'localhost'  # what IP address(es) to listen on;
 60                               # comma-separated list of addresses;
 61                         # defaults to 'localhost'; use '*' for all
 62                                         # (change requires restart)
 63 #port = 5432                            # (change requires restart)
 修改端口时，默认把前面#去掉，不修改的话默认为5432
 #修改完后重启服务
 #systemctl restart postgresql

8、修改数据库log相关的参数

# - Where to Log -

#log_destination = 'stderr'    # Valid values are combinations of
                               # stderr, csvlog, syslog, and eventlog,
                             # depending on platform.  csvlog
                              # requires logging_collector to be on.

# This is used when logging to stderr:
logging_collector = on       # Enable capturing of stderr and csvlog
#日志默认为打开
                             # into log files. Required to be on for
                                        # csvlogs.
                              # (change requires restart)

# These are only used if logging_collector is on:
#log_directory = 'pg_log'    # directory where log files are written,
                             # can be absolute or relative to PGDATA
log_filename = 'postgresql-%a.log'      # log file name pattern,
                              # can include strftime() escapes
#log_file_mode = 0600                   # creation mode for log files,
                              # begin with 0 to use octal notation
log_truncate_on_rotation = on   # If on, an existing log file with the
                              # same name as the new log file will be
                             # truncated rather than appended to.
                             # But such truncation only occurs on
                            # time-driven rotation, not on restarts
                            # or size-driven rotation.  Default is
                            # off, meaning append to existing files
                            # in all cases.
log_rotation_age = 1d       # Automatic rotation of logfiles will
#日志只保存一天
                            # happen after that time.  0 disables.
log_rotation_size = 0       # Automatic rotation of logfiles will
                             # happen after that much log output.
                              # 0 disables.

9、内存参数的设置

# - Memory -

shared_buffers = 32MB                   # min 128kB
#共享内存的大小，用于共享数据块

10、添加用户、创建数据库、并登录

#授权用户远程登录
#vim /var/lib/pgsql/data/pg_hba.conf	#在最后一行添加
host	all		all		0.0.0.0/0 		md5
#vim /var/lib/pgsql/data/postgresql.conf
listen_addresses='*'		#把localhost更改为*
#systemctl restart postgresql
#创建用户和密码
postgres=# create user wang01 with password '123456';
CREATE ROLE
#创建数据库，基于用户wang01
postgres=# create database test01 owner wang01;
CREATE DATABE
#授权用户
postgres=# grant all privileges on database test01 to wang01;
GRANT
#查看结果
postgres=# \l
                             List of databases
   Name    |  Owner   | Encoding  | Collate | Ctype |   Access privileges
-----------+----------+-----------+---------+-------+-----------------------
 postgres  | postgres | SQL_ASCII | C       | C     |
 template0 | postgres | SQL_ASCII | C       | C     | =c/postgres          +
           |          |           |         |       | postgres=CTc/postgres
 template1 | postgres | SQL_ASCII | C       | C     | =c/postgres          +
           |          |           |         |       | postgres=CTc/postgres
 test      | wang     | SQL_ASCII | C       | C     | =Tc/wang             +
           |          |           |         |       | wang=CTc/wang
 test01    | wang01   | SQL_ASCII | C       | C     | =Tc/wang01           +
           |          |           |         |       | wang01=CTc/wang01
 test02    | postgres | SQL_ASCII | C       | C     |
(6 rows)

#登录
[root@centos7 data]# psql -h 10.0.0.3 -p 5432 -U wang -d test
Password for user wang:
psql (9.2.24)
Type "help" for help.

test=> \l
                             List of databases
   Name    |  Owner   | Encoding  | Collate | Ctype |   Access privileges
-----------+----------+-----------+---------+-------+-----------------------
 postgres  | postgres | SQL_ASCII | C       | C     |
 template0 | postgres | SQL_ASCII | C       | C     | =c/postgres          +
           |          |           |         |       | postgres=CTc/postgres
 template1 | postgres | SQL_ASCII | C       | C     | =c/postgres          +
           |          |           |         |       | postgres=CTc/postgres
 test      | wang     | SQL_ASCII | C       | C     | =Tc/wang             +
           |          |           |         |       | wang=CTc/wang
(4 rows)

11、postgresql数据库基本应用

1、列出所有数据库
mysql: show databases
psql:    \l或\list
2、切换数据库
mysql:  use dbname
psql:     \c dbname
3、列出当前数据库下的所有表
mysql:  show tables
psql:       \d
4、列出指定表的所有字段
mysql:   shwo columns from table_name
psql:    \d table_name
5、查看表的基本情况
mysql:  describe table_name
psql:    \d+ table_name