$sth = $dbh->prepare ($sql);
# im doing a mysql restart
$sth->execute (); # DBD::mysql magically reconnects keeping the prepared statement and executes

##</code><code>##

$sth= $dbh->prepare ($sql);
# stoping mysql
$sth->execute (); # DBD::mysql tries, but no connection, reconnecting and trying again will lose the $dbh->prepare 

##</code><code>##

$sth= $dbh->prepare ($sql);
# stoping mysql
$sth->execute (); # entering reconnect mode in MyDBI::st/db: 
while (!$dbh->ping) { 
sleep 5; 
MyDBI->connect_like_mysql_reconnects;
}