PostgreSQL 8.4 no levenshtein fuzzymatching?
You have to install the additional module fuzzystrmatch.

In PostgreSQL 9.1 or later, simply run CREATE EXTENSION once per database:

CREATE EXTENSION fuzzystrmatch;


In PostgreSQL 8.4 on Debian Squeeze, you would run as OS postgres matching the DB superuser postgres (so with peer authentication without PW) the SQL script provided by the package postgresql-contrib-8.4 (install that if you haven't already):

sudo -u postgres psql mydb -f /usr/share/postgresql/8.4/contrib/fuzzystrmatch.sql


About CREATE EXTENSION:


Do I need to execute &quot;create extension pgcrypto&quot; everytime?