#!/bin/bash
# names have been changed to protect the guilty
cred="user=dbadmin password=SECRET"
domain=example.com

tee
   >( psql -X "host=db1.$domain dbname=db1 $cred" )
   >( psql -X "host=db2.$domain dbname=db2 $cred" )
   >( psql -X "host=db3.$domain dbname=db3 $cred" )
   >( psql -X "host=xdb1.$domain dbname=xdb1 $cred" )
   > /dev/null
wait

tee "${p[@]}" > /dev/null

tee: /dev/fd/63: No such file or directory

p=()
for z in db1 db2 db3 xdb1
do
  p+=( >( psql -X "host=$z.$domain dbname=$z $cred" ) )
done
tee "${p[@]}" > /dev/null