failure on system update for lack of gpg key

[David Bear <David.Bear@xxxxxxx>]

while running yum update, yum stopped with the following message:

warning: rpmts_HdrFromFdno: header V3 DSA signature: NOKEY, key ID e8e345b8 pgdg83/gpgkey

public key for postgresql-server.... is not installed.

is there a quick how-to or guide on getting the correct gpg installed? 

--
David Bear
College of Public Programs at ASU
602-494-0424