.. _os_postgres_install:

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Installing PostgreSQL and PostGIS
=================================

Install PostgreSQL
------------------

Update the packages list::

   yum check-update
   
Install the package for configuring the PGDG repository::

   yum install http://yum.postgresql.org/9.4/redhat/rhel-7-x86_64/pgdg-centos94-9.4-1.noarch.rpm
 
EPEL repository will provide GDAL packages::

   yum install http://mirror.sfo12.us.leaseweb.net/epel/7/x86_64/e/epel-release-7-5.noarch.rpm 

Install PostgreSQL, PostGIS and related libs::

   yum install postgis2_94 postgresql94 postgresql94-server postgresql94-libs postgresql94-contrib postgresql94-devel gdal geos
   yum install gdal-python python-pip python-imaging  python-virtualenv python-devel gcc-c++ python-psycopg2
   yum install libxml2 libxml2-devel libxml2-python libxslt libxslt-devel libxslt-python


Verify::

   rpm -qa | grep postg
  
   postgresql94-libs-9.4.4-1PGDG.rhel7.x86_64
   postgis2_94-2.1.8-1.rhel7.x86_64
   postgresql94-9.4.4-1PGDG.rhel7.x86_64
   postgresql94-devel-9.4.4-1PGDG.rhel7.x86_64
   postgresql94-contrib-9.4.4-1PGDG.rhel7.x86_64
   postgresql94-server-9.4.4-1PGDG.rhel7.x86_64  
  
Init the DB::

   /usr/pgsql-9.4/bin/postgresql94-setup initdb
   
Enable start on boot::

   systemctl enable postgresql-9.4.service
   
Start postgres service by hand::

   systemctl start postgresql-9.4.service
      
To restart or reload the instance, you can use the following commands::

   systemctl restart postgresql-9.4.service
   systemctl reload postgresql-9.4.service
  

Setting PostgreSQL access
-------------------------

Edit the file ``/var/lib/pgsql/9.4/data/pg_hba.conf`` so that the local connection entries 
will change to::

  # "local" is for Unix domain socket connections only

  local   all             postgres                                peer
  local   all             all                                     md5

  # IPv4 local connections:

  host    all             postgres        127.0.0.1/32            ident
  host    all             all             127.0.0.1/32            md5

  # IPv6 local connections:
  host    all             postgres        ::1/128                 ident
  host    all             all             ::1/128                 md5


Once the configuration file has been edited, restart postgres::

   systemctl restart postgresql-9.4.service