CentOS7 RPM离线安装PG12的办法

https://pkgs.org/search/?q=postgresql12

postgresql12-12.3-1PGDG.rhel7.x86_64.rpm
postgresql12-contrib-12.3-1PGDG.rhel7.x86_64.rpm
postgresql12-libs-12.3-1PGDG.rhel7.x86_64.rpm
postgresql12-server-12.3-1PGDG.rhel7.x86_64.rpm

#注意 PGDG 应该是安装资源库的 可以不安装
#contrib 是安装扩展的 没有这个包就没有 ossp-uuid的插件了
#server 是数据库的安装文件
#libs 用来客户端进行连接. 
#注意 如果是centos8 的话 选择 rhel8 进行下载就可以了.

yum localinstall *.rpm

[root@CentOS76 PG12]# systemctl status postgresql-12
● postgresql-12.service - PostgreSQL 12 database server
   Loaded: loaded (/usr/lib/systemd/system/postgresql-12.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Tue 2020-05-26 13:15:00 CST; 4min 18s ago
     Docs: https://www.postgresql.org/docs/12/static/
  Process: 7355 ExecStartPre=/usr/pgsql-12/bin/postgresql-12-check-db-dir ${PGDATA} (code=exited, status=1/FAILURE)

May 26 13:15:00 CentOS76 systemd[1]: Starting PostgreSQL 12 database server...
May 26 13:15:00 CentOS76 systemd[1]: postgresql-12.service: control process exited, code=exited status=1
May 26 13:15:00 CentOS76 systemd[1]: Failed to start PostgreSQL 12 database server.
May 26 13:15:00 CentOS76 systemd[1]: Unit postgresql-12.service entered failed state.
May 26 13:15:00 CentOS76 systemd[1]: postgresql-12.service failed.

[Unit]
Description=PostgreSQL 12 database server
Documentation=https://www.postgresql.org/docs/12/static/
After=syslog.target
After=network.target

[Service]
Type=notify

User=postgres
Group=postgres

# Note: avoid inserting whitespace in these Environment= lines, or you may
# break postgresql-setup.

# Location of database directory
Environment=PGDATA=/var/lib/pgsql/12/data/

# Where to send early-startup messages from the server (before the logging
# options of postgresql.conf take effect)
# This is normally controlled by the global default set by systemd
# StandardOutput=syslog

# Disable OOM kill on the postmaster
OOMScoreAdjust=-1000
Environment=PG_OOM_ADJUST_FILE=/proc/self/oom_score_adj
Environment=PG_OOM_ADJUST_VALUE=0

ExecStartPre=/usr/pgsql-12/bin/postgresql-12-check-db-dir ${PGDATA}
ExecStart=/usr/pgsql-12/bin/postmaster -D ${PGDATA}
ExecReload=/bin/kill -HUP $MAINPID
KillMode=mixed
KillSignal=SIGINT
 

# Do not set any timeout value, so that systemd will not kill postmaster
# during crash recovery.
TimeoutSec=0

[Install]
WantedBy=multi-user.target

切换到PG的用户
su - postgres

切换到 PG 的默认程序目录

cd /usr/pgsql-12/bin/

执行初始化数据库的脚本
./initdb -D /var/lib/pgsql/12/data/

systemctl enable  postgresql-12 && systemctl restart postgresql-12

su - postgres
进入postgresql 数据库
执行命令
psql
修改管理员的密码:
alter role postgres with password 'Test1127?!';

修改默认配置文件
vim /var/lib/pgsql/12/data/pg_hba.conf
在客户端安全配置的地方增加一行.

host    all             all             0.0.0.0/0         md5
# 注意 trust 就是默认免密, md5 是默认加密.
修改数据库其他配置信息

vim /var/lib/pgsql/12/data/postgresql.conf

# 监听所有地址的请求 注意测试环境可以,开发环境需要与防火墙一同设置, 将listen_addresses 后面的localhost 修改为 * 并且去掉前面的注释.

listen_addresses = '*' 
注意也需要同步将port 前面的注释去掉. 

# 修改 连接数 可以将max_connections的数值改大.

max_connections = 1000

systemctl restart  postgresql-12