(PHP 4 >= 4.3.0, PHP 5)
pg_ping — Ping database connection
$connection
  ] )pg_ping() pings a database connection and tries to reconnect it if it is broken.
connection
       PostgreSQL database connection resource.  When 
       connection is not present, the default connection 
       is used. The default connection is the last connection made by 
       pg_connect() or pg_pconnect().
      
   Returns TRUE on success or FALSE on failure.
  
Example #1 pg_ping() example
<?php 
$conn = pg_pconnect("dbname=publisher");
if (!$conn) {
  echo "An error occurred.\n";
  exit;
}
if (!pg_ping($conn))
  die("Connection is broken\n");
?>