$ sudo apt-get update
$ sudo apt-get install aolserver4-nspostgres 

aolserver4-nspostgres is installed in your system.

Make ensure the aolserver4-nspostgres package were installed using the commands given below,

$ sudo dpkg-query -l | grep aolserver4-nspostgres *

You will get with aolserver4-nspostgres package name, version, architecture and description in a table

aolserver4-nspostgres package basic information: