In this article, I have explained about PostgreSQL Database 12.1 installation on Red Hat Linux / CentOS
- PostgreSQL is an open-source database management system.
- It is designed to run on different platforms.
- Its source code is available under PostgreSQL license.
- PostgreSQL supports both SQL for relational and NoSQL for non-relational queries.
- Rpm, yum, source installation methods are explained in PostgreSQL database
The Hardware Requirement
Memory Requirement
The minimum requirement of physical RAM is 2GB.
RAM Memory
The minimum requirement for memory.
$ grep MemTotal /proc/meminfo
Swap Memory
$ grep SwapTotal /proc/meminfo
System architecture
The system architecture of the OS is 64bit.
$ uname -m
Disk space Requirement
The tmp directory should contain a free disk space of 1GB or more.
$ df -h /tmp
The Software Requirement
Operating system Requirement
The OS version is Red Hat Enterprise Linux 7/8 and centos.
The kernel version is 2.6.32.
$ cat /proc/version
Package Requirement
The following are the installed packages with version.
(In PostgreSQL Database 12 prior to release 12.1.0, package both 64-bit and 32-bit shown in the following table is required.)
$ Rpm-q package postgres
rpm -ivh postgresql12-libs-12.1-1 PGDG.rhel7.x86_64.rpm
rpm -ivh postgresql12-12.1-1PGDG.rhel7.x86_64.rpm
rpm -ivh postgresql12-contrib-12.1-1PGDG.rhel7.x86_64.rpm
rpm -ivh postgresql12-server-12.1-1PGDG.rhel7.x86_64.rpm
PostreSQL Installation
We can install PostgreSQL using any one of the below types.
RPM-Manual Installation
If you cannot, or do not want to, use the yum-based installation method, all the RPMs that are in the yum repository are available for direct download and manual installation as well.
YUM -Online Installation
The PostgreSQL Yum Repository will integrate with your normal systems and patch management, and provide automatic updates for all supported versions of PostgreSQL throughout the supported lifetime of PostgreSQL.
The PostgreSQL Yum Repository currently supports,
- Red Hat Enterprise Linux
- CentOS
- Scientific Linux
- Postgres Linux
- Fedora*
SOURCE - Requirement Installation
Using the make, make all commands we can create a new source based on our requirements
Rpm Installation
Pre-request (Enter the root user)
Data path and user creation,
Create “postgres“user
Useradd postgres
Passwd postgres
Create data path /var/lib/data12pgsql
Chmod -R 755 data12pgsql/
Chown -R postgres. data12pgsql/
bin path creation:
Created bin path automatically in /usr while initdb start.
Postgresql 12.1 Installation steps
Step 1 - Download and install Repo
Link: https://yum.postgresql.org/12/redhat/rhel-7-x86_64/
[root@svgen Software]# rpm -ivh pgdg-redhat-repo-42.0-11.noarch.rpm
Preparing... ################################# [100%]
Step 2 - Download the needed “Rpm”from below link
Link: https://download.postgresql.org/pub/repos/yum/12/redhat/rhel-7-x86_64/
[root@gokul Postgres_sw]# Rpm are saved in the “Postgres_sw” directory
rpm -ivh postgresql12-libs-12.1-1 PGDG.rhel7.x86_64.rpm
rpm -ivh postgresql12-12.1-1PGDG.rhel7.x86_64.rpm
rpm -ivh postgresql12-contrib-12.1-1PGDG.rhel7.x86_64.rpm
rpm -ivh postgresql12-server-12.1-1PGDG.rhel7.x86_64.rpm
Step 3 - Switch user su - postgres
[postgres@gokul ~]$
/usr/pgsql-12/bin/initdb -D /var/lib/data12pgsql
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.
The database cluster will be initialized with locale "en_US.UTF-8".
The default database encoding has accordingly been set to "UTF8".
The default text search configuration will be set to "english".
Data page checksums are disabled.
Success. You can now start the database server using,
/usr/pgsql-12/bin/pg_ctl -D /var/lib/data12pgsql -l logfile start
Step 4 - Start the service
/usr/pgsql-12/bin/pg_ctl -D /var/lib/data12pgsql status
/usr/pgsql-12/bin/pg_ctl -D /var/lib/data12pgsql start
/usr/pgsql-12/bin/pg_ctl -D /var/lib/data12pgsql stop
[postgres@gokul ~]$ /usr/pgsql-12/bin/pg_ctl -D /var/lib/data12pgsql start
server started.
Step 5 - Connect the database
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Post Installation – Configuration
cd /var/lib/data12pgsql
vi pg_hba.conf
# IPv4 local connections:
host all all ::1/128 ident
host all all 0.0.0.0/0 trust
vi postgresql.conf
listen_addresses = 'db.gokulakrishna.me' # what IP address(es) to listen on;
port = 5432 # (change requires restart)
max_connections = 100 # (change requires restart)
Note
After the configuration file is edited we must restart the service for changes replication.
Step 7 - Remote Access
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Yum Installation
To use the PostgreSQL Yum Repository, follow these steps,
![Postgresql Installation and Uninstallation]()
/usr/pgsql-12/bin/postgresql-12-setup initdb
systemctl enable postgresql-12.service
systemctl start postgresql-12.service
Post Installation – Configuration
cd /var/lib/psql/12/datal
vi pg_hba.conf
# IPv4 local connections:
host all all ::1/128 ident
host all all 0.0.0.0/0 trust
vi postgresql.conf
listen_addresses = '10.1.4.78' # what IP address(es) to listen on;
port = 5432 # (change requires restart)
max_connections = 300 # (change requires restart)
Note
After the configuration file is edited we must restart the service for changes replication.
Remote Access
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Source Installation
Step 1
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Step 2
![Postgresql Installation and Uninstallation]()
STEP 3
Place the file in /opt/source location.
[root@postgres source]# pwd
/opt/source
Unzip the tar file
[root@ postgres source]# tar -zxvf postgresql-12.0.tar.gz
Step 4
[root@postgres source]# ll
drwxrwxrwx. 6 1107 1107 4096 Jan 31 14:43 postgresql-12.0
-rw-r--r--. 1 root root 26393892 Jan 31 13:01 postgresql-12.0.tar.gz
[root@postgres source]# cd postgresql-12.0/
Step 5
[[email protected]]# ll
total 1204
drwxrwxrwx. 2 1107 1107 4096 Oct 1 01:39 config
Step 6
./configure --prefix=/var/lib/pg1sql
Step 7
make
make install
Step 8
mkdir /var/lib/data
chmod 700 /data
chown -R postgres. Data
Step 9
su - postgres
cd /var/lib/pg1sql/bin
-bash-4.2$ cd pg1sql/
-bash-4.2$ ll
drwxr-xr-x. 2 root root 4096 Jan 31 14:50 bin
-bash-4.2$ cd bin/
-bash-4.2$ ll
-rwxr-xr-x. 1 root root 142520 Jan 31 14:50 initdb
Step 10
.-bash-4.2$ ./initdb -D /var/lib/data
Step 11
-bash-4.2$ ./pg_ctl --help
pg_ctl is a utility to initialize, start, stop, or control a PostgreSQL server.
Usage
pg_ctl init[db] [-D DATADIR] [-s] [-o OPTIONS]
pg_ctl start [-D DATADIR] [-l FILENAME] [-W] [-t SECS] [-s]
[-o OPTIONS] [-p PATH] [-c]
pg_ctl stop [-D DATADIR] [-m SHUTDOWN-MODE] [-W] [-t SECS] [-s]
pg_ctl restart [-D DATADIR] [-m SHUTDOWN-MODE] [-W] [-t SECS] [-s]
[-o OPTIONS] [-c]
pg_ctl reload [-D DATADIR] [-s]
pg_ctl status [-D DATADIR]
pg_ctl promote [-D DATADIR] [-W] [-t SECS] [-s]
pg_ctl logrotate [-D DATADIR] [-s]
pg_ctl kill SIGNALNAME PID
Common options
-D, --pgdata=DATADIR location of the database storage area
-s, --silent only print errors, no informational messages
-t, --timeout=SECS seconds to wait when using -w option
-V, --version output version information, then exit
-w, --wait wait until operation completes (default)
-W, --no-wait do not wait until operation completes
-?, --help show this help, then exit
If the -D option is omitted, the environment variable PGDATA is used.
Options for stop or restart
-m, --mode=MODE MODE can be "smart", "fast", or "immediate"
Shutdown modes are,
Smart - quit after all clients have disconnected
Fast - quit directly, with proper shutdown (default)
Immediate - quit without complete shutdown; will lead to recovery on restart
Allowed signal names for kill,
ABRT HUP INT KILL QUIT TERM USR1 USR2
Step 12 - HOW TO STOP SERVICE
-bash-4.2$ pwd
/var/lib/pg1sql/bin
postgres-# \q
-bash-4.2$ ./pg_ctl -D /var/lib/data stop
waiting for the server to shut down.... done.
server stopped.
Step 13 - HOW TO START SERVICE
-bash-4.2$ ./pg_ctl -D /var/lib/data start
waiting for server to start....2020-02-03 17:57:07.810 IST [10281] LOG: starting PostgreSQL 12.0 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39), 64-bit
2020-02-03 17:57:07.810 IST [10281] LOG: listening on IPv4 address "10.1.4.88", port 5432
2020-02-03 17:57:07.811 IST [10281] LOG: listening on Unix socket "/tmp/.s.PGSQL.5432"
2020-02-03 17:57:07.820 IST [10282] LOG: database system was shut down at 2020-02-03 17:54:01 IST
2020-02-03 17:57:07.826 IST [10281] LOG: database system is ready to accept connections
done.
server started.
Step 14 - HOW TO STATUS SERVICE
-bash-4.2$ ./pg_ctl -D /var/lib/data status
pg_ctl: server is running (PID: 10281)
/var/lib/pg1sql/bin/postgres "-D" "/var/lib/data"
Step 15
postgres 7125 7124 0 14:34 pts/1 00:00:00 -bash OS LEVEL FIND OUT SERVICE STATUS
[root@postgres source]# ps -ef |grep postgres
postgres 10281 1 0 17:57 ? 00:00:00 /var/lib/pg1sql/bin/postgres -D /var/lib/data
Step 16
-bash-4.2$ ./pg_ctl -D /var/lib/data status
pg_ctl: server is running (PID: 10281)
/var/lib/pg1sql/bin/postgres "-D" "/var/lib/data"
-bash-4.2$ ./psql -p 5432
psql (12.0)
Type "help" for help.
postgres=#
Step 17
postgres=# \l
List of database,
postgres=# \dn
List of schemas,
Post Installation – Configuration
cd /var/lib/psql/12/datal
vi pg_hba.conf
# IPv4 local connections:
host all all ::1/128 ident
host all all 0.0.0.0/0 trust
vi postgresql.conf
listen_addresses = '10.1.4.78' # what IP address(es) to listen on,
port = 5432 # (change requires restart)
max_connections = 300 # (change requires restart)
Note
After the configuration file is edited we must restart the service for changes replication.
Remote Access
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Postgresql Uninstall
Uninstall 11.7 version
Pre-Request for uninstalling
- . Enter the postgres user and we need to stop the postmaster service.
- . Remove the list of rpm
- . Remove the bin path and data-path
- . Remove the Postgres user
Step 1 - stop the service
[postgres@gokul ~]$ /usr/pgsql-11/bin/pg_ctl -D /var/lib/datapg11.7 status
/usr/pgsql-11/bin/postgres "-D" "/var/lib/datapg11.7"pg_ctl: server is running (PID: 2236)
[postgres@gokul ~]$ /usr/pgsql-11/bin/pg_ctl -D /var/lib/datapg11.7 stop
waiting for server to shut down.... done
server stopped
Step 2 - remove rpm from gokul Environment
[root@gokul ~]# rpm -qa | grep postgres
postgresql11-libs-11.7-1PGDG.rhel7.x86_64
postgresql11-11.7-1PGDG.rhel7.x86_64
postgresql11-server-11.7-1PGDG.rhel7.x86_64
postgresql11-contrib-11.7-1PGDG.rhel7.x86_64
[root@gokul ~]#rpm -e postgresql11-11.7-1PGDG.rhel7.x86_64
[root@gokul ~]#rpm -e postgresql11-server-11.7-1PGDG.rhel7.x86_64
[root@gokul ~]#rpm -e postgresql11-libs-11.7-1PGDG.rhel7.x86_64
[root@gokul ~]#rpm -e postgresql11-contrib-11.7-1PGDG.rhel7.x86_64
Step 3 - Enter the “root” user remove the bin path and data path from gokul environment
Bin path removal,
[root@gokul ~]# cd /usr
[root@gokul usr]# rm -rf pgsql-11
Data path removal,
[root@gokul ~]# cd /var/lib
[root@gokul lib]# rm -rf datapg11.7
Step 4 - Removal of postgres user
[root@gokul ~]# userdel -r postgres
Successfully uninstalled 11.7 version