CentOS6.7安装PostgreSQL10.9详细教程

前  言

PostgreSQL 是一个基于 POSTGRES 的对象关系数据库管理系统（ORDBMS），版本4.2，由加州大学伯克利分校计算机科学系开发。POSTGRES 开创了许多概念，这些概念在很久以后才在某些商业数据库系统中出现。

PostgreSQL 最初设想于 1986 年，当时被叫做 Berkley Postgres Project。该项目一直到 1994 年都处于演进和修改中，直到开发人员 Andrew Yu 和 Jolly Chen 在 Postgres 中添加了一个 SQL（StructuredQuery Language，结构化查询语言）翻译程序，该版本叫做Postgres95，在开放源代码社区发放。1996 年，再次对 Postgres95 做了较大的改动，并将其作为 PostgresSQL6.0 版发布。一般 Linux 系统自带了 Postgresql,但比较旧，不太好用，工欲善其事，必先利其器，那么我们来安装一个比较合适的版本吧。

一、 软件包下载

进入 PostgreSQL 官网 https://www.postgresql.org/

点击 Download 然后选择相对应的安装方式，我这里选择源码安装，点击 Source 选择相应的版本，我这里选择的是 10.9 版本，如下图所示。

当点击版本时会出现两种格式 .bz2 和 .gz 格式，一般会选择 压缩后较小的 .bz2  格式，注意观察，文件下两行有 .md5 和 .sha256 格式的文件，此文件记录了使用对应加密算法加密第一行文件的完整的加密算法值，当下载完文件后用于比对下载文件的完整性。

点击第二个文件查看其中的 MD5 加密值如下：

62f755219b9b05c25f24737405a5aae1  postgresql-10.9.tar.bz2

下载完之后，由于服务器一般都属于内网环境，无法上网，则通过 SFTP 上传至服务器 /home/postgresql 目录，然后检验 MD5 值，保证软件下载过程中没有损坏，可正常使用，下面是检验出来的 MD5 值与上图下载中的一致，说明软件可正常使用。

[root@JiekeXupostgresql]# md5sum postgresql-10.9.tar.bz2
62f755219b9b05c25f24737405a5aae1  postgresql-10.9.tar.bz2
[root@JiekeXupostgresql]# ll -lh
total 19M
-rw-r--r-- 1 rootroot 19M Jul  7 23:29postgresql-10.9.tar.bz2

二、 操作系统相关配置

1、内核参数设置

vi /etc/sysctl.conf

############################forpostgresql###########
kernel.shmall =4294967296
kernel.shmmax=135497418752
kernel.shmmni =4096
kernel.sem = 5010064128000 50100 1280
fs.file-max =7672460
fs.aio-max-nr =1048576
net.ipv4.ip_local_port_range= 9000 65000
net.core.rmem_default= 262144
net.core.rmem_max= 4194304
net.core.wmem_default= 262144
net.core.wmem_max= 4194304
net.ipv4.tcp_max_syn_backlog= 4096
net.core.netdev_max_backlog= 10000
net.ipv4.netfilter.ip_conntrack_max= 655360
net.ipv4.tcp_timestamps= 0
net.ipv4.tcp_tw_recycle=1
net.ipv4.tcp_timestamps=1
net.ipv4.tcp_keepalive_time= 72
net.ipv4.tcp_keepalive_probes= 9
net.ipv4.tcp_keepalive_intvl= 7
vm.zone_reclaim_mode=0
vm.dirty_background_bytes= 40960000
vm.dirty_ratio =80
vm.dirty_expire_centisecs= 6000
vm.dirty_writeback_centisecs= 50
vm.swappiness=0
vm.overcommit_memory= 0
vm.overcommit_ratio= 90

 使用命令 sysctl -p  使其生效

2、操作系统的限制

这些在安装 Oracle 和 MySQL 已经说过，这里就不再说明了。

vi /etc/security/limits.conf  

* soft    nofile 131072 
* hard    nofile 131072 
* soft    nproc  131072 
* hard    nproc  131072 
* soft    core   unlimited 
* hard    core   unlimited 
* soft    memlock 500000000 
* hard    memlock 500000000

3、limits.d 目录

此目录下的文件也是文件限制，上文已经设置了，这里如果还存在的话，则以此文件限制为准，故删除。

more /etc/security/limits.d/90-nproc.conf
# Default limit for number of user's processes toprevent
# accidental fork bombs.
# See rhbz #432903 for reasoning.
 
*          soft   nproc     1024
root       soft   nproc     unlimited

系统其它普通用户最多进程默认是 1024 个，而 root 用户是 unlimited (不受限制）

ls /etc/security/limits.d/*
rm -f /etc/security/limits.d/*

4、关闭selinux 和 防火墙

vi /etc/sysconfig/selinux   

SELINUX=disabled 
SELINUXTYPE=targeted

需要关闭 SELINUX 和 操作系统防火墙 iptables

设置 selinux 为 disable 并重启操作系统；用 chkconfig iptables off 命令关闭防火墙。

5、配置yum 本地源，安装以下依赖包

yum -y install coreutils glib2 lrzsz mpstat dstatsysstat e4fsprogs xfsprogs ntp readline-devel zlib-devel openssl-develpam-devel libxml2-devel libxslt-devel python-devel tcl-devel gcc makesmartmontools flex bison perl-devel perl-Ext Utils* openldap-devel jadetex openjade bzip2

 

6、创建普通用户

useradd postgresql 
passwd postgresql

7、建立数据目录并上传、解压安装包

su – postgresql
mkdir pgdata
tar -xvf postgresql-10.9.tar.bz2

做一个软链接方便以后管理与升级

ln -s postgresql-10.9 postgresql

8、编译安装

使用如下命令进行编译安装

cd /home/postgresql/postgresql
./configure --prefix=/home/postgresql/postgresql--with-perl --with-python

make world -j 4 
make install-world

编译过程中的部分日志

gcc -Wall -Wmissing-prototypes -Wpointer-arith-Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute-Wformat-security -fno-strict-aliasing -fwrapv -O2 -fPIC -shared -o pgcrypto.sopgcrypto.o px.o px-hmac.o px-crypt.o crypt-gensalt.o crypt-blowfish.o crypt-des.ocrypt-md5.o md5.o sha1.o internal.o internal-sha2.o blf.o rijndael.opgp-mpi-internal.o imath.o mbuf.o pgp.o pgp-armor.o pgp-cfb.o pgp-compress.opgp-decrypt.o pgp-encrypt.o pgp-info.o pgp-mpi.o pgp-pubdec.o pgp-pubenc.opgp-pubkey.o pgp-s2k.o pgp-pgsql.o -L../../src/port -L../../src/common   -Wl,--as-needed-Wl,-rpath,'/home/postgresql/pgdata/lib',--enable-new-dtags   -lz
make[2]: Leaving directory`/home/postgresql/postgresql-10.9/contrib/pgcrypto'
make[1]: Leaving directory `/home/postgresql/postgresql-10.9/contrib'
PostgreSQL, contrib, and documentation successfullymade. Ready to install.

9、环境变量配置

编辑 postgresql 家目录下的 .bashrc文件，添加如下所示内容，注意这里不推荐使用 .bash_profile 文件或者 .profile 文件，因为有时候在图形化界面中打开终端，这两个文件不生效。如果此配置文件对所有用户生效，则需要配置 /etc/profile 文件。

[postgresql@JiekeXu ~]$ vi .bashrc
export PS1="$USER@`/bin/hostname -s`->" 
export PGPORT=5432 
export PGDATA=/home/postgresql/pgdata 
export.utf8 
export PGHOME=/home/postgresql/postgresql
exportLD_LIBRARY_PATH=$PGHOME/lib:/lib64:/usr/lib64:/usr/local/lib64:/lib:/usr/lib:/usr/local/lib:$LD_LIBRARY_PATH 
export PATH=$PGHOME/bin:$PATH:. 
export DATE=`date +"%Y%m%d%H%M"` 
export MANPATH=$PGHOME/share/man:$MANPATH 
export PGHOST=$PGDATA 
export PGUSER=postgres 
export PGDATABASE=postgres 
alias rm='rm -i' 
alias ll='ls -lh' 

使其生效，退出重新登陆或者 source 。

source .bashrc

10、创建数据库簇（即初始化数据库）

initdb -D  $PGDATA -E UTF8 --locale=C -U postgres

postgresql@JiekeXu-> initdb -D  $PGDATA -E UTF8 --locale=C -U postgres
The files belonging to this database system will beowned by user "postgresql".
This user must also own the server process.
 
The database cluster will be initialized with locale"C".
The default text search configuration will be set to"english".
 
Data page checksums are disabled.
 
fixing permissions on existing directory /home/postgresql/pgdata... ok
creating subdirectories ... ok
selecting default max_connections ... 100
selecting default shared_buffers ... 128MB
selecting default timezone ... PRC
selecting dynamic shared memory implementation ...posix
creating configuration files ... ok
running bootstrap script ... ok
performing post-bootstrap initialization ... ok
syncing data to disk ... ok
 
WARNING: enabling "trust" authentication forlocal connections
You can change this by editing pg_hba.conf or usingthe option -A, or
--auth-local and --auth-host, the next time you runinitdb.
 
Success. You can now start the database server using:
 
    pg_ctl -D/home/postgresql/pgdata -l logfile start
 
postgresql@JiekeXu->

11、contrib 工具安装

contrib 下面有一些比较使用的工具，我们也可以选择安装一下，基本上直接编译、安装即可。

cd /home/postgresql/postgresql/contrib
make
make install

12、数据库配置文件相关

在数据目录下编辑两个配置文件 postgresql.conf和pg_hba.conf

（1）配置文件

cd $PGDATA

vi postgresql.conf

listen_addresses = '0.0.0.0' 
port = 5432 
max_connections = 200 
unix_socket_directories = '.' 
tcp_keepalives_idle = 60 
tcp_keepalives_interval = 10 
tcp_keepalives_count = 10 
shared_buffers = 512MB 
dynamic_shared_memory_type = posix 
vacuum_cost_delay = 0 
bgwriter_delay = 10ms 
bgwriter_lru_maxpages = 1000 
bgwriter_lru_multiplier = 10.0 
bgwriter_flush_after = 0  
old_snapshot_threshold = -1 
backend_flush_after = 0  
wal_level = replica 
synchronous_commit = off 
full_page_writes = on 
wal_buffers = 16MB 
wal_writer_delay = 10ms 
wal_writer_flush_after = 0  
checkpoint_timeout = 30min  
max_wal_size = 1GB 
min_wal_size = 128MB 
checkpoint_completion_target = 0.05   
checkpoint_flush_after = 0   
random_page_cost = 1.3  
log_destination = 'csvlog' 
logging_collector = on 
log_truncate_on_rotation = on 
log_checkpoints = on 
log_connections = on 
log_disconnections = on 
log_error_verbosity = verbose 
autovacuum = on 
log_autovacuum_min_duration = 0 
autovacuum_naptime = 20s 
autovacuum_vacuum_scale_factor = 0.05 
autovacuum_freeze_max_age = 1500000000 
autovacuum_multixact_freeze_max_age = 1600000000 
autovacuum_vacuum_cost_delay = 0 
vacuum_freeze_table_age = 1400000000 
vacuum_multixact_freeze_table_age = 1500000000 
datestyle = 'iso, mdy' 
timezone = 'PRC' 
lc_messages = 'C' 
lc_monetary = 'C' 
lc_numeric = 'C' 
lc_time = 'C' 
default_text_search_config = 'pg_catalog.english' 
shared_preload_libraries='pg_stat_statements'

（2）配置pg_hba.conf

数据库防火墙文件名字 pg_hba.conf，将以下内容追加到文件末尾，表示允许网络用户使用用户密码连接到你的 postgresql 数据库.

host      all          all             0.0.0.0/0               md5

（3）数据库启动并查看相关状态、进程

postgresql@JiekeXu-> pg_ctl start
postgresql@JiekeXu-> pg_ctl status
pg_ctl: no server running

那么，相应的停止命令则为：pg_ctl stop [-m SHUTDOWN-MODE]

postgresql@JiekeXu-> pg_ctl stop
waiting for server to shut down.... done
server stopped

注意：-m 参数时指定数据库停止方式，有 smart、fast、immediate，一般这三个都会简写成“-ms”,”-mf”,”-mi”。smart 则是等所有的连接终止后，关闭数据库。如果数据库一直有连接则无法关闭。fast 则是快速关闭数据库，断开客户端连接，让已有的事务回滚，然后正常关闭数据库，这相当于 oracle数据库的 shutdown immediate模式。而 immediate 则是立即关闭数据库，相当于数据库进程立即停止，直接退出，下次启动数据库需要恢复，这则是相当于 Oracle 数据库关闭时的 shutdown abort 模式，慎用。

三、数据库简单操作示例

以上配置好数据库，可以进行简单的操作学习了，使用 psql 直接进入数据库，如同oracle 里的 sqlplus 命令。

首先第一个就是 help 命令，详细信息如下：

postgresql@JiekeXu-> psql --help
psql is the PostgreSQL interactiveterminal.
 
Usage:
 psql [OPTION]... [DBNAME [USERNAME]]
 
General options:
  -c,--command=COMMAND    run only singlecommand (SQL or internal) and exit
  -d,--dbname=DBNAME      database name toconnect to (default: "postgres")
  -f,--file=FILENAME      execute commandsfrom file, then exit
  -l,--list               list availabledatabases, then exit
  -v,--set=, --variable=NAME=VALUE
                           set psql variable NAME to VALUE
                           (e.g., -vON_ERROR_STOP=1)
  -V,--version            output versioninformation, then exit
  -X,--no-psqlrc          do not read startupfile (~/.psqlrc)
  -1("one"), --single-transaction
                           execute as a singletransaction (if non-interactive)
  -?,--help[=options]     show this help, thenexit
     --help=commands      listbackslash commands, then exit
     --help=variables     list specialvariables, then exit
 
Input and output options:
  -a,--echo-all           echo all input fromscript
  -b,--echo-errors        echo failed commands
  -e,--echo-queries       echo commands sentto server
  -E,--echo-hidden        display queries thatinternal commands generate
  -L,--log-file=FILENAME  send session log tofile
  -n,--no-readline        disable enhancedcommand line editing (readline)
  -o,--output=FILENAME    send query resultsto file (or |pipe)
  -q,--quiet              run quietly (nomessages, only query output)
  -s,--single-step        single-step mode(confirm each query)
  -S,--single-line        single-line mode(end of line terminates SQL command)
 
Output format options:
  -A,--no-align           unaligned tableoutput mode
  -F,--field-separator=STRING
                           field separator forunaligned output (default: "|")
  -H,--html               HTML table outputmode
  -P,--pset=VAR[=ARG]     set printing optionVAR to ARG (see \pset command)
  -R,--record-separator=STRING
                          recordseparator for unaligned output (default: newline)
  -t,--tuples-only        print rows only
  -T,--table-attr=TEXT    set HTML table tagattributes (e.g., width, border)
  -x,--expanded           turn on expandedtable output
  -z,--field-separator-zero
                           set field separatorfor unaligned output to zero byte
  -0,--record-separator-zero
                           set record separatorfor unaligned output to zero byte
 
Connection options:
  -h,--host=HOSTNAME      database server hostor socket directory (default: "/home/postgresql/pgdata")
  -p,--port=PORT          database server port(default: "5432")
  -U,--username=USERNAME  database user name(default: "postgres")
  -w,--no-password        never prompt forpassword
  -W,--password           force passwordprompt (should happen automatically)
 
For more information, type "\?"(for internal commands) or "\help" (for SQL
commands) from within psql, or consult thepsql section in the PostgreSQL
documentation.
 
Report bugs to<[e-mail]>.

根据以上信息，使用 psql 进入数据库，相当于 Oracle 数据库的 SQL plus 命令。这样也可以查看数据库的版本亦或者使用 pgsql –V 也可以查看数据库版本。

\help  --帮助信息
\l     --列出当前系统所有数据库信息
postgres-# \help
Available help:
 ABORT                           CREATE FOREIGN TABLE            DROP SCHEMA
 ALTER AGGREGATE                  CREATE FUNCTION                  DROP SEQUENCE
 ALTER COLLATION                 CREATE GROUP                    DROP SERVER
 ALTER CONVERSION                CREATE INDEX                    DROP STATISTICS
 ALTER DATABASE                   CREATE LANGUAGE                  DROP SUBSCRIPTION
 ALTER DEFAULT PRIVILEGES        CREATE MATERIALIZED VIEW        DROP TABLE
 ALTER DOMAIN                    CREATE OPERATOR                 DROP TABLESPACE
 ALTER EVENT TRIGGER             CREATE OPERATOR CLASS           DROP TEXT SEARCH CONFIGURATION
 ALTER EXTENSION                 CREATE OPERATOR FAMILY          DROP TEXT SEARCH DICTIONARY
 ALTER FOREIGN DATA WRAPPER      CREATE POLICY                   DROP TEXT SEARCH PARSER
 ALTER FOREIGN TABLE             CREATE PUBLICATION              DROP TEXT SEARCH TEMPLATE
 ALTER FUNCTION                  CREATE ROLE                     DROP TRANSFORM
 ALTER GROUP                     CREATE RULE                     DROP TRIGGER
  ALTERINDEX                      CREATESCHEMA                    DROP TYPE
 ALTER LANGUAGE                  CREATE SEQUENCE                 DROP USER
 ALTER LARGE OBJECT              CREATE SERVER                   DROP USER MAPPING
 ALTER MATERIALIZED VIEW         CREATE STATISTICS               DROP VIEW
 ALTER OPERATOR                  CREATE SUBSCRIPTION             END
 ALTER OPERATOR CLASS            CREATE TABLE                    EXECUTE
 ALTER OPERATOR FAMILY           CREATE TABLE AS                 EXPLAIN
 ALTER POLICY                    CREATE TABLESPACE               FETCH
 ALTER PUBLICATION               CREATE TEXT SEARCH CONFIGURATION GRANT
 ALTER ROLE                      CREATE TEXT SEARCH DICTIONARY   IMPORT FOREIGN SCHEMA
 ALTER RULE                      CREATE TEXT SEARCH PARSER       INSERT
 ALTER SCHEMA                    CREATE TEXT SEARCH TEMPLATE     LISTEN
 ALTER SEQUENCE                  CREATE TRANSFORM                LOAD
 ALTER SERVER                     CREATE TRIGGER                   LOCK
 ALTER STATISTICS                CREATE TYPE                     MOVE
 ALTER SUBSCRIPTION              CREATE USER                     NOTIFY
 ALTER SYSTEM                    CREATE USER MAPPING              PREPARE
 ALTER TABLE                     CREATE VIEW                     PREPARE TRANSACTION
 ALTER TABLESPACE                DEALLOCATE                      REASSIGN OWNED
 ALTER TEXT SEARCH CONFIGURATION DECLARE                          REFRESHMATERIALIZED VIEW
 ALTER TEXT SEARCH DICTIONARY    DELETE                          REINDEX
 ALTER TEXT SEARCH PARSER        DISCARD                         RELEASE SAVEPOINT
 ALTER TEXT SEARCH TEMPLATE      DO                               RESET
 ALTER TRIGGER                   DROP ACCESS METHOD              REVOKE
 ALTER TYPE                      DROP AGGREGATE                  ROLLBACK
 ALTER USER                      DROP CAST                       ROLLBACK PREPARED
 ALTER USER MAPPING              DROP COLLATION                  ROLLBACK TO SAVEPOINT
 ALTER VIEW                      DROP CONVERSION                 SAVEPOINT
 ANALYZE                         DROP DATABASE                   SECURITY LABEL
 BEGIN                            DROP DOMAIN                      SELECT
 CHECKPOINT                      DROP EVENT TRIGGER              SELECT INTO
 CLOSE                           DROP EXTENSION                  SET
 CLUSTER                         DROP FOREIGN DATA WRAPPER       SET CONSTRAINTS
 COMMENT                         DROP FOREIGN TABLE              SET ROLE
 COMMIT                          DROP FUNCTION                   SET SESSION AUTHORIZATION
 COMMIT PREPARED                 DROP GROUP                       SET TRANSACTION
 COPY                            DROP INDEX                      SHOW
 CREATE ACCESS METHOD            DROP LANGUAGE                   START TRANSACTION
 CREATE AGGREGATE                DROP MATERIALIZED VIEW           TABLE
 CREATE CAST                     DROP OPERATOR                   TRUNCATE
 CREATE COLLATION                DROP OPERATOR CLASS             UNLISTEN
 CREATE CONVERSION               DROP OPERATOR FAMILY            UPDATE
 CREATE DATABASE                 DROP OWNED                      VACUUM
 CREATE DOMAIN                   DROP POLICY                     VALUES
 CREATE EVENT TRIGGER            DROP PUBLICATION                WITH
 CREATE EXTENSION                DROP ROLE                        
 CREATE FOREIGN DATA WRAPPER     DROP RULE                       

postgres-# \l
                             List of databases
  Name    |  Owner  | Encoding | Collate | Ctype |  Access privileges  
-----------+----------+----------+---------+-------+-----------------------
 postgres | postgres | UTF8     | C       | C    |
 template0 | postgres | UTF8     | C      | C     | =c/postgres          +
          |          |          |         |      | postgres=CTc/postgres
 template1 | postgres | UTF8     | C      | C     | =c/postgres          +
          |          |          |         |      | postgres=CTc/postgres
(3 rows)

创建数据库，查看数据库，删除数据库

postgres=# create database JiekeXu;
CREATE DATABASE
postgres=# \l
                            List ofdatabases
  Name    |  Owner  | Encoding | Collate | Ctype |  Access privileges  
-----------+----------+----------+---------+-------+-----------------------
 jiekexu  | postgres | UTF8     | C       | C    |
 postgres | postgres | UTF8     | C       | C    |
 template0 | postgres | UTF8     | C      | C     | =c/postgres          +
          |          |          |         |      | postgres=CTc/postgres
 template1 | postgres | UTF8     | C      | C     | =c/postgres          +
          |          |          |         |      | postgres=CTc/postgres
 testdb   | postgres | UTF8     | C       | C    |
(5 rows)
 
postgres=# drop database TestDB;
DROP DATABASE
postgres=# \l
                             List of databases
  Name    |  Owner  | Encoding | Collate | Ctype |  Access privileges  
-----------+----------+----------+---------+-------+-----------------------
 jiekexu  | postgres | UTF8     | C       | C    |
 postgres | postgres | UTF8     | C       | C    |
 template0 | postgres | UTF8     | C      | C     | =c/postgres          +
          |          |          |         |      | postgres=CTc/postgres
 template1 | postgres | UTF8     | C      | C     | =c/postgres          +
          |          |         |         |       | postgres=CTc/postgres
(4 rows)

创建表，查看表，删除表

切换数据库

postgres=# \c jiekexu
You are now connected to database"jiekexu" as user "postgres".

创建表

jiekexu=# create table test(id int,namechar(20), age int);
CREATE TABLE
jiekexu=#
jiekexu=# insert into  test values(1,'JiekeXu',18);
INSERT 0 1
jiekexu=# insert into  test values(2,'Adventure',25);
INSERT 0 1
jiekexu=#

查看表信息

jiekexu=# \d
        List of relations
 Schema | Name | Type  |  Owner  
--------+-------+-------+----------
 public | test | table | postgres
 public | test1 | table | postgres
 public | test2 | table | postgres
(3 rows)
 
jiekexu=# \d  test
                   Table"public.test"
 Column |    Type      | Collation | Nullable |Default
--------+---------------+-----------+----------+---------
 id     |integer       |          |          |
 name   |character(20) |           |          |
 age    |integer

查看表内容

jiekexu=# select * from test;
 id|         name         | age
----+----------------------+-----
  1 |JiekeXu              |  18
  2 |Adventure            |  25
(2 rows)

修改表内容

jiekexu=# update test set age=26 wherename='JiekeXu';
UPDATE 1
jiekexu=# commit;
WARNING: there is no transaction in progress
COMMIT
jiekexu=# select * from test;
 id|         name         | age
----+----------------------+-----
  2 |Adventure            |  25
  1 |JiekeXu              |  26
(2 rows)

删除表

drop table test2;
delete from test;

jiekexu=# select * from test;
 id|         name         | age
----+----------------------+-----
  2 |Adventure            |  25
  1 |JiekeXu              |  26
  2 |BreatHeat            |  22
(3 rows)
 
jiekexu=# delete  from test where age=22;
DELETE 1
jiekexu=# select * from test;
 id|         name         | age
----+----------------------+-----
  2 |Adventure            |  25
  1 |JiekeXu              |  26
(2 rows)
jiekexu=# drop table test2;
DROP TABLE
jiekexu=#
jiekexu=# \d
        List of relations
 Schema | Name | Type  |  Owner  
--------+-------+-------+----------
 public | test | table | postgres
 public | test1 | table | postgres
(2 rows)

最后，使用 \q 或者 Ctrl + d 退出命令行

jiekexu-# \q
postgresql@JiekeXu->

---

断断续续、零零散散、慢慢悠悠的花了一周的时间， 写了这么一点儿东西，希望可以帮助更多的 PGer ，我们一同学习，共同进步，前进的路上不孤单，加油！一起努力向前！如有写的不当之处，还请批评指正，谢谢！最后，容我开一次赞赏，看着你的头像出现在下方，将是我很开心的一件事儿！

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