PostgreSQL_installtion

# Install and configure PostgreSQL server on CentOS

# centos by default contains postgresql packages just install through yum
yum install postgresql-server postgresql-contrib

# Before using postgresql initialize PGDATA to up postgresql server
postgresql-setup initdb

# enable host base authentication to postgres database
# To do ,open /var/lib/pgsql/data/pg_hba.conf and change ident to md5
host    all             all             127.0.0.1/32            md5
host    all             all             ::1/128                 md5 

# Open port in firewall for postgresql 
firewall-cmd --permanent --add-port=5432/tcp
firewall-cmd --permanent --add-port=80/udp

# reload firewall-cmd to take place changes
firewall-cmd --reload

# Adjust SELinux flag for postgresql
setsebool -P httpd_can_network_connect_db 1
 
# start and enable postgresql
systemctl start postgresql
systemctl enable postgresql

# create role and database
sudo -i -u postgres

# in postgre bash terminal create user
createuser --interactive

# in same postgre bash terminal create database
createdb <DB>

# access postgres db terminal
psql

# select dabatabase
psql -d <DB>

# install adminpack for postgresql
# please install this command in db terminal
CREATE EXTENSION adminpack;

# database info # \conninfo
# quit database # \q
# list tables in database # \d