How to install PGXN on RHEL6

Installing PGXN on RHEL 6.3 is not as easy as it might sound.

First you need to install the PostgreSQL yum repo:
rpm -ivh http://yum.postgresql.org/9.2/redhat/rhel-6.3-x86_64/pgdg-redhat92-9.2-7.noarch.rpm

Then you need to install pgxnclient:
yum install pgxnclient

The pgxn client has 2 dependencies which are not listed in the package:

• setuptools
• simplejson 2.1

To satisfy the first dependency we need to install python-setuptools
yum install python-setuptools

The second one is not that easy as the simplejson version in RHEL6.3 is 2.0, which is too old. We can use PIP to install a newer version:
yum remove python-simplejson
yum install python-pip python-devel
python-pip install simplejson

And now the pgxn command will work.