Simply add one or more pools to your config.tcl file as in the following example.
ns_section ns/db/pools
ns_param pool1 "Pool 1"
ns_param pool2 "Pool 2"
ns_param pool3 "Pool 3"
ns_param pool4 "Pool 4"
.....
ns_section ns/db/pool/pool4
ns_param maxidle 1000000000
ns_param maxopen 1000000000
ns_param connections 5
ns_param verbose $debug
ns_param extendedtableinfo true
ns_param logsqlerrors $debug
ns_param driver postgres
ns_param datasource remotehostaddress::remotedbname
ns_param user $user_account
ns_param password ""
Note also that your remote db must be configured to accept IP connections (set tcpip_socket = true in your postgresql.conf).
