It's possible to set a per-database connection limit of < -1, which seems bogus:
gator:~ dpage$ /usr/local/pgsql84/bin/psql -p 5433 postgres
psql (8.4devel)
Type "help" for help.
postgres=# create database test with connection limit = -999;
CREATE DATABASE
postgres=# select datname, datconnlimit from pg_database;
datname | datconnlimit
-----------+--------------
template1 | -1
template0 | -1
postgres | 50
foo | 45
test | -999
(5 rows)
8.3 seems similarly afflicted - I haven't tested any further back.
--
Dave Page
EnterpriseDB UK: http://www.enterprisedb.com