Postgresql 15的安装及简单使用

1 下载、安装及数据库初始化

下载安装postgresql官方yam仓库,使用yum install命令完成

下载安装postgresql15-server

    Error: Package: postgresql15-server-15.1-1PGDG.rhel7.x86\_64 (pgdg15)
               Requires: libzstd.so.1()(64bit)
    Error: Package: postgresql15-15.1-1PGDG.rhel7.x86\_64 (pgdg15)
               Requires: libzstd.so.1()(64bit)
    Error: Package: postgresql15-15.1-1PGDG.rhel7.x86\_64 (pgdg15)
               Requires: libzstd >= 1.4.0
     You could try using --skip-broken to work around the problem
     You could try running: rpm -Va --nofiles --nodigest

有一个依赖包（libzstd）需要手动安装安装以下，版本不能低于1.4.0

[root@localhost ~\]# rpm -ivh libzstd-1.5.2-1.el7.x86\_64.rpm

再次安装postgresql15-server后，进行数据库初始化。

[root@localhost ~\]/usr/pgsql-15/bin/postgresql-15-setup initdb

设置数据库开机自动启动后启动数据库

[root@localhost ~\]systemctl enable postgresql-15
[root@localhost ~\]systemctl start postgresql-15

2 登录数据库及数据库的简单使用

检查postgresql数据库的操作系统用户

[root@localhost ~\]# cat /etc/passwd
    postgres:x:26:26:PostgreSQL Server:/var/lib/pgsql:/bin/bash

切换至数据库用户

[root@localhost ~\]# su -  postgres
    -bash-4.2$

登录数据库

-bash-4.2$ psql
    psql (15.1)
    Type "help" for help.

显示现有数据库

                                                    List of databases
      Name    |  Owner   | Encoding |   Collate   |    Ctype    | ICU Locale | Locale Provider |   Access privileges
   -----------+----------+----------+-------------+-------------+------------+-----------------+-----------------------
    postgres  | postgres | UTF8     | en\_US.UTF-8 | en\_US.UTF-8 |            | libc            |
    template0 | postgres | UTF8     | en\_US.UTF-8 | en\_US.UTF-8 |            | libc            | =c/postgres          +
              |          |          |             |             |            |                 | postgres=CTc/postgres
    template1 | postgres | UTF8     | en\_US.UTF-8 | en\_US.UTF-8 |            | libc            | =c/postgres          +
              |          |          |             |             |            |                 | postgres=CTc/postgres
   (3 rows)

退出到操作系统下，查看postgresql的后台进程

[root@localhost ~\]# top -b -u postgres -d 1 -n 1 -c
    top - 03:17:36 up 54 min,  1 user,  load average: 0.00, 0.01, 0.05
    Tasks: 116 total,   2 running, 114 sleeping,   0 stopped,   0 zombie
    %Cpu(s):  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
    KiB Mem : 12028356 total, 10859232 free,   481980 used,   687144 buff/cache
    KiB Swap:  6160380 total,  6160380 free,        0 used. 11264344 avail Mem

      PID USER      PR  NI    VIRT    RES    SHR S %CPU %MEM     TIME+ COMMAND
     2070 postgres  20   0  401252  17368  15920 S  0.0  0.1   0:00.04 /usr/pgsql-15/bin/postmaster -D /var/lib/pgsql/15/d+
     2072 postgres  20   0  253084   2148    720 S  0.0  0.0   0:00.00 postgres: logger
     2073 postgres  20   0  401404   2316    812 S  0.0  0.0   0:00.00 postgres: checkpointer
     2074 postgres  20   0  401388   3368   1872 S  0.0  0.0   0:00.37 postgres: background writer
     2076 postgres  20   0  401388   6272   4780 S  0.0  0.1   0:00.08 postgres: walwriter
     2077 postgres  20   0  402872   3356   1588 S  0.0  0.0   0:00.00 postgres: autovacuum launcher
     2078 postgres  20   0  402852   3088   1356 S  0.0  0.0   0:00.00 postgres: logical replication launcher

[root@localhost ~\]# ps -fu postgres
     UID        PID  PPID  C STIME TTY          TIME CMD
     postgres  1010     1  0 01:02 ?        00:00:00 /usr/pgsql-15/bin/postmaster -D /var/lib/pgsql/15/data/
     postgres  1067  1010  0 01:02 ?        00:00:00 postgres: logger
     postgres  1076  1010  0 01:02 ?        00:00:00 postgres: checkpointer
     postgres  1077  1010  0 01:02 ?        00:00:00 postgres: background writer
     postgres  1089  1010  0 01:02 ?        00:00:00 postgres: walwriter
     postgres  1090  1010  0 01:02 ?        00:00:00 postgres: autovacuum launcher
     postgres  1091  1010  0 01:02 ?        00:00:00 postgres: logical replication launcher

看一下数据库状态

-bash-4.2$ export PATH=$PATH:/usr/pgsql-15/bin
-bash-4.2$ pg\_ctl status
     pg\_ctl: server is running (PID: 1010)
     /usr/pgsql-15/bin/postgres "-D" "/var/lib/pgsql/15/data/"

创建数据库，连接数据库，创建表

postgres=# create database test;
     CREATE DATABASE
postgres=# \\c test
     You are now connected to database "test" as user "postgres".
test=# create table test (id int, name varchar(20));
     CREATE TABLE
test=# insert into test values (1, 'test');
     INSERT 0 1
test=# select \* from test;
      id | name
     ----+------
       1 | test
     (1 row)

远程连接数据库，首先创建用户，授予权限

CREATE ROLE
postgres=# alter database test owner to test;
     ALTER DATABASE
test=# alter table test owner to test;
     ALTER TABLE

这里直接把test数据库和test表的owner更换为新建的用户，由于数据库的owner是在创建表之后改的，表的owner也需要改一下。

编辑一下数据库data目录里的pg_hba.conf.conf,加入下面一行

host    test        all             192.168.0.0/16       md5

第三列的all允许用户连接所有的数据库，这样test用户就可以从192.168网段的任一地址连接到数据库了